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Counting Backwards: Winning Methods with the
Widmark & Retrograde Extrapolation
Presented by Brian Cox
Defending The Modern DUII
OCDLA - Eugene - March 7 - 8, 2014
- or - ???
What Is Retrograde Extrapolation?
Retrograde extrapolation is the term for a scientific analysis looking at someone's blood-alcohol
level at the time of testing and calculating the alcohol level at a prior point in time. In other
words, retrograde extrapolation is simply mathematics - with many built-in assumptions.
Understanding the strengths and weaknesses of multiplying an elimination rate by a time factor,
however, requires knowledge of toxicology, pharmacology, physiology, metabolism and related
fields, making it the province of expert witnesses. Disagreements between experts about the
variables and correct elimination rates to be applied go to the weight of the evidence, as do the
differences in the experts’ credentials.
Who the Heck Is Widmark & Why Do We Care?
Swedish physician E.M.P. Widmark is credited with doing much of the foundational research
regarding alcohol kinetics in the human body during the early part of the 20 century. In addition,th
he developed an algebraic equation allowing one to estimate any one of six variables given the
other five in order to calculate blood alcohol concentration. According to Widmark’s equation,
the amount of alcohol consumed (A) is a function of these several variables.
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The Widmark Formula can be expressed in a long (set out at the end of the materials) or a short
form. Many (so called) expert witnesses attempt to only use the short form, which can lead to
inaccuracies in the calculation; even the long form of Widmark's formula is not 100% accurate.
The Basic Widmark Formula is as follows: % BAC = (A x 5.14 / W x r) - .015 x H
Note: All of Widmark's work was done on subjects who drank a metered amount
of alcohol on an empty stomach. In the original test group of 30 subjects, only 3
(10%) tested in the absorption range of 0.65 and 0.70, 19 (63%) tested under 0.65,
and 8 (27%) tested over 0.65. The subjects' elimination rates varied from 0.006 to
0.04 with most being widely distributed between 0.010 and 0.020.
"A" is the total number of ounces of alcohol ingested by the individual starting at
the first drink.
"5.14" is a mathematical conversion factor (.823 x 100/16) used to convert liquid
ounces to regular weighted ounces, with the "100" used to convert the final value
to a percentage, and lastly, "16" is used to convert pounds to ounces.
"W" stands for the weight of the individual consuming the alcohol, while "r" is the
distribution ratio for alcohol through the body. For men, "r" stands for 0.73, while
for women the value is 0.66.
“.015" is the ‘average’ used to represent the alcohol elimination (dissipation) rate. A
range from 0.010 to 0.025% can appropriately be used.
Lastly, "H" is the period of time, in hours, that alcohol was eliminated from the
body -- in other words, how quickly the alcohol finished going though the
bloodstream and then was processed by the liver, thereby losing the potent effect
of the alcohol itself. Typically, "H" is equal to the time between the first drink and
the time the BAC calculations are being made (typically the time of driving).
Key to BAC levels and the Widmark Formula is the idea that all people share the same or very
similar parameters for alcohol absorption and elimination through the body. This includes
distribution of alcohol through the bloodstream, meaning how long it takes a drink to work its
way through your body before the BAC reading will reach its true mark. While rough estimates
place people at the same values for each of these traits, the truth is that people vary in each phase
of BAC calculations, and involves a number of other factors that cannot be ignored.
Alcohol Metabolism Explained:
The three stages of alcohol metabolism are
absorption, distribution, and elimination.
• Absorption is the process by which the body
accepts alcohol into the bloodstream.
• Distribution is how the alcohol moves
throughout the body.
• Elimination is the process by which alcohol
is broken down or removed from the body.
Absorption:
Absorption is the process by which alcohol is made available to the fluids of distribution of the
body, such as blood, plasma, serum, etc. Typically, about 80 percent of orally-consumed alcohol
is absorbed from the small intestines, with the rest absorbed from the stomach. On an empty
stomach, more than half of the alcohol consumed will be absorbed within 15 minutes and a
maximum blood level will occur in about 20 minutes, with 80 to 90 percent complete absorption
occurring within 30 to 60 minutes.
Numerous variables affect alcohol absorption and estimation, including the rate of consumption,
how much is consumed, the alcohol's concentration, the presence of carbonation in the drinks,
food in the stomach, whether the person is taking any medications that can interfere with the
gastrointestinal tract, as well as other variables including:
• Drinking Pattern • Absorption Time
• Food Intake • Individual Variables
- Additional Variables Effecting Absorption:
• Type of alcohol ingested • Whether alcohol/food ingested was
• Illness carbonated or uncarbonated
• Medications • Gender
• Stimulants (may slow absorption) • Pathological Conditions
• Trauma (may slow absorption) • Fatigue/amount of sleep
• Race (possibly)
Alcohol Elimination (Metabolism):
The third process is elimination (metabolism). To ultimately remove alcohol from the body, it
must first be inactivated. This is initiated by altering the alcohol's chemical structure into a
substance that is more easily excreted by the body, and is often referred to as detoxification.
Alcohol is metabolized in the liver by the enzyme dehydrogenase into acetaldehyde, which
causes dilation of blood vessels (It’s this dilation that is responsible for hangovers). The
acetaldehyde is next metabolized by the enzyme aldehyde dehydrogenase into acetate, which is
very similar to vinegar. Measurement of blood serum acetate levels may be an indicator of
problem or chronic drinking. Certain drugs can inhibit the aldehyde dehydrogenase enzyme
responsible for the second step in metabolizing alcohol, and inhibition of this enzyme causes an
increase in blood acetaldehyde levels. One of these drugs is antabuse, which is often used to treat
alcoholics. People taking antabuse can become very sick from consuming even a small amount of
alcohol. Other such drugs include chloral hydrate and oral anti-diabetic drugs such as Diabinese.
Studies show that typically, 80 percent of consumed alcohol enters the blood within five to 10
minutes, 100 percent enters the blood within 30 to 60 minutes, and that alcohol is eliminated
from the blood at a rate between .01 and .025 percent per hour. The state crime lab uses .010 to
.020 as a ‘standard’ elimination rate (viewed by the State as representing someone with a lower
metabolism and benefitting the defendant), though studies demonstrate that individual
elimination rates can vary from .008 - .036% per hour.
When to Challenge: Pre-trial or Mid-trial?
One way to challenge scientific evidence is through a pretrial motion. Under ORS 135.037, you
have a right to a pretrial omnibus hearing to determine issues including "[s]uppression of
evidence." "Suppression" has been interpreted quite broadly for purposes of another statute (ORS
138.060, governing the State's right to take interlocutory appeals); at least in that context, it's not
limited to constitutionally based suppression motions. See State v. Hoare, 20 Or App 439 (1975);
State v. Koennecke, 274 Or 169 (1976). In addition to that statutory language, Oregon case law
approves the idea of a pretrial hearing on the admissibility of scientific evidence or other
evidence with significant prejudicial potential. See State v. O'Key, 321 Or 285, 307 n 29 (1995)
("When proffered scientific evidence raises issues of scientific validity, those issues should be
addressed by the trial court in a separate OEC 104(1) hearing, preferably in advance of trial." See
also e.g. State v. Stanley, 30 Or App 33, 38 (1977) (“Evidence which carries an unusual potential
for prejudice should be ruled upon preliminarily, prior to trial in the case of State's evidence . .")).
Alternatively, you can wait until the point in the trial where the State seeks to introduce the
evidence, and demand that a proper foundation be laid before that evidence comes in. You should
be able to have the jury excluded for this portion - if they're present, they're exposed not only to
proffered scientific evidence that may ultimately be deemed inadmissible, but also to the
inadmissible portions of the foundational evidence. See OEC 103(3) ("In jury cases, proceedings
should be conducted, to the extent practicable, so as to prevent inadmissible evidence from being
suggested to the jury by any means . . . ."); OEC 104(3) (hearings on preliminary matters other
than the admissibility of confessions should be conducted outside the jury's presence "when the
interests of justice require").
There are advantages and disadvantages to both options. If you file a pretrial motion, you know
going into trial whether you'll have to deal with that evidence or not. Of course, the State knows
this too, so depending on the circumstances the preparation factor may be a wash. If you win
such a motion, you don't have to worry about the jury hearing about the evidence in the early
phases of the trial. Cf. State v. Stanley, supra, 30 Or App at 196 (affirming conviction although
evidence referenced early in the trial was ultimately deemed inadmissible: "Where there was no
pretrial motion, where both attorneys had mentioned breathalyzer evidence prior to the officer's
testimony, and where the reason for the exclusion of the evidence reflects negatively upon the
reliability of that evidence, we cannot say as a matter of law that the hearing of foundation
evidence before the jury influenced the jury in their fact-finding . . . ").
A pretrial motion may more generally alert the prosecution and make them more prepared than
they would otherwise be. This is particularly significant where the type of evidence at issue hasn't
been approved by any Oregon appellate court, so that the prosecutors must lay the entire
Brown/O'Key foundation - no small thing. A prosecutor challenged to do so mid-trial may not be
ready with sufficient evidence of scientific validity, error rates, peer-reviewed literature, and all
the other factors in the analysis/record to fill the foundational-void. However, if you file a pretrial
motion and succeed in getting the evidence excluded, the State has an appeal right that it
wouldn't have if the exclusion decision had been made mid-trial. See State v. Hoare, supra, 20
Or App at 444-45 ("When a defendant raises an objection to evidence in advance of trial, he
takes the risk that the State may have an opportunity to obtain review of an adverse decision it
would otherwise be deprived of if the objection were made during the course of the
proceedings."). For this reason, the State may itself ask for a pretrial hearing on the admissibility
of its evidence, especially if you've alerted them to the fact that you intend to challenge it.
Remember: The proponent of the scientific evidence has the burden of establishing its validity.
State v. Perry, 347 Or 110, 122 (2009). This is important in retrograde extrapolation cases,
because the mathematical process underlying retrograde extrapolation is based on two
assumptions: (1) that at the time of the breath test the defendant was in the eliminative phase of
his/her intoxication, when his/her BAC level was decreasing, and (2) that the defendant's blood
was eliminating alcohol at a specific rate. To properly determine whether the defendant was in
the eliminative phase of intoxication and at what rate the defendant's blood was eliminating
alcohol, the criminalist conducting the retrograde extrapolation must take into account several
factors applying a range of elimination rates as opposed to a specific value. Without
consideration of these factors, retrograde extrapolation should not be considered scientifically-
valid. As aptly described by the Alabama Court of Appeals: “[T]he inadequacies of retrograde
extrapolation extend beyond mere technical inaccuracies to problems which are inherent in the
basic premises and calculations of this technique. These inadequacies render retrograde
extrapolation inherently untrustworthy and therefore inappropriate for use as evidence to convict
drunk drivers.'") (quoting E. Abbott, "One for the Road" - The Reliability of Retrograde
Extrapolation and the Implications for Vermont Statutes, 16 VT.L.Rev. 395, 397 (1991)). Smith
v. Tuscaloosa, 601 So. 2d 1136, 1140 (Ala. Crim. App. 1992).
To Cross or Not to Cross - That Is the Question:
Another decision is how extensive and searching your cross-examination of the proffered expert
should be during the admissibility hearing, whether pretrial or mid-trial. Prosecutors sometimes
show up apparently thinking of the Brown/O'Key factors as a fairly perfunctory list of yes/no
questions. ("Mr.Ms. Expert, has this method been confirmed through studies?" "Yes." "Is there
peer-reviewed literature on this method?" "Yes." etc.). If the prosecutor is not well-versed in the
law in this area, he or she may simply try to lay only a bare-bones, possibly legally-insufficient
foundation.
What to do then? One option is to dive into a heavy, thorough cross-examination that exposes the
lack of any legitimate basis for the witness's conclusory statements. For example, the State's
witnesses may have given testimony on direct regarding error rates, but a good cross might reveal
that those rates were not determined by any legitimate, quantitative process. Or the "studies"
relied on to validate the State's method might have been done internally, by technicians, without
the "studies" having been subjected to peer review or otherwise validated. Cf. State v. Perry, 347
Or 110, (2009) ("[The witness] also described a small, informal CARES study of children with
abnormal physical examinations, which found that 90 percent of those children had delayed in
disclosing sexual abuse. She acknowledged that the study was not peer reviewed and was not
rigorous. We do not consider it as part of the State's portrayal of specialized literature at the OEC
104 hearing.").
Remember: at an admissibility hearing, it's not a "sufficiency of the evidence" standard - the
evidence only comes in if the court actually decides by a preponderance of the evidence that it's
valid. See State v. O'Key, supra, 321 Or at 307 n 29 ("Under OEC 104(1), the trial court is not to
decide merely that the proponent has offered enough evidence of validity to enable a reasonable
person to conclude that the evidence is valid, but the court is to decide the validity issue."). If you
can demonstrate on cross that the witness's conclusory direct testimony was unfounded and
should be given little weight, you might move the court’s thinking in your direction in the
admissibility analysis.
But: it's also possible for that sort of cross to produce testimony that would allow a trial or
appellate court to fill the gaps and find the evidence admissible. For that reason, you may decide
you're better off with little or no cross, just leaving the record as the State has created it. One
thing to note if you're going to try the "minimalist" route: to be safe, you probably need to
mention all of the Brown/O'Key factors in your argument before the trial court, or at least all of
the ones that might give you some traction on appeal. Otherwise, even though it's the State's
burden to lay the foundation for its evidence, you could be deemed to have effectively conceded
the unmentioned factors. See State v. Perry, supra, 347 Or at 122 ("In general, we agree with the
premise of the State's argument: in multi-factor foundation cases like the present one, for
example, the trial court reasonably might assume that some factors are not in dispute if no one
mentioned them.").
As you can see, there's no universal answer to questions such as whether to make your challenge
pretrial or mid-trial and how extensively to cross the State's witnesses. The decisions should be
made in light of the various objectives of a Brown/O’Key hearing; these include winning the
admissibility argument at the trial court level, developing and preserving a basis for an appeal,
and previewing the State's evidence and potentially weakening it at trial (as to this last objective,
many of the issues affecting the admissibility analysis will also provide useful cross examination
material at trial, and in the admissibility hearing without the jury present you can ask probing
questions with comparatively little risk even if you don't know the answers).
What To Expect From The State:
The State, through the testimony of a crime lab expert, tends to rely heavily upon the Gullberg
studies to support the use and admission of retrograde analysis evidence. See Rodney Gullberg,
Variation in Blood Alcohol Concentration Following the Last Drink, 10 J. of Police Science &
Admin. 289 (1982); Gullberg & McElroy, Comparing Roadside With Subsequent Breath Alcohol
Analysis & Their Relevance To the Issue Of Retrograde Extrapolation, 57 Forensic Science
International 193 (1992).
State Crime Lab Experts:
When you're challenging the State's scientific evidence, you'll find yourself in one of two basic
situations and dealing with one of two kinds of “expert” witnesses. Though ostensibly-neutral
scientists employed by the State to perform various kinds of analysis and testing, in fact each
employs various levels of advocacy for the State. Such expert witnesses typically provide
evidence establishing the foundation for use of retrograde extrapolation evidence, or more
commonly, evidence establishing the application of retrograde extrapolation.
If the evidence is of a type that's been previously approved by an Oregon appellate court (for
example, HGN evidence in a DUII case), the admissibility requirements are relatively limited;
the State basically has to show that the witness is qualified to apply the method or technique and
did so correctly in your case. See, e.g., State v. O'Key, 321 Or 285, 293 n 8 (1995). However,
absent such appellate approval, the State needs to lay a much more comprehensive foundation.
The distinction between the expert witnesses role (and qualification) for establishing foundation
vs. application is an important one to keep in mind whenever the State has to lay a full
Brown/O'Key foundation. Pay close attention to the qualifications of the witness the State puts
forward at the admissibility hearing, as you may find out that the State’s ‘foundation expert’ is
only qualified to testify to the application, not the underlying science. Is that witness a true
"foundation-level" expert? Is s/he qualified to explain the scientific principles underlying the test,
how it works, what the potential sources of error are, etc.? (Note: "qualified" means more than
being able to read those things out of a book or manual and regurgitate them to the court.). Or is
the State’s expert someone who knows how to do the test (like the police officer in State v. Rood,
83 Or App 451 (1987))? Remember, the key focus is not whether the witness gives foundational
evidence (much as a police officer or lab tech is capable of doing) but whether the witness is
qualified to testify to the scientific principles supporting the use of retrograde extrapolation.
- A Random Sampling of State “Experts”:
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Please Note: All ‘rankings’ are purely subjective and are based on the author’s
personal experience together with a non-scientific telephone/email poll of a number
of experienced Oregon criminal defense lawyers.
Robert Jones: ‘Ranked’ [by defense counsel] as mostly neutral, with mild-to-moderate
moments of advocacy for the State. Acknowledges non-supportive
information/studies in his testimony, and is typically willing to acknowledge
shortcomings in analysis/science.
Paul Refalo: ‘Ranked’ [by defense counsel] as the most adversarial and strongest advocate for
the State’s position in a given case. Tends to omit non-supportive
information/studies in his testimony, exposing himself to multiple impeachment
and/or ‘why didn’t the State tell us this’ opportunities.
Jennifer Bray: ‘Ranked’ [by defense counsel] as mostly neutral, with mild-to-moderate
moments of advocacy for the State. Acknowledges non-supportive
information/studies in her testimony, is often able to respond by offering contra
studies and crime lab procedural/confirmation testing, typically willing to
acknowledge shortcomings in analysis/science.
Case Example
Q. "What do you know about rates of absorption?”
A. "Well rates of absorption that’s not something we study with our blood-breath
correlation studies, I can tell you what is in the literature it’s just that it’s very highly
variable from individual to individual and even with the same individual from day to
day you can have different absorption rates * * * there are so many factors that can
be involved with that. What kind of drink it was, was it carbonated or not, is there any
food in the stomach, is that person * * * under a lot of stress are they relaxed different
things can affect how fast that alcohol is absorbed.”
Testimony of Robert Jones
State v.Vaughn - Clackamas Co Case CR08-10989 [September 7, 2008]
Case Example
See transcript from State v. Rubic, Clackamas Co. Case CR10-14169 [June 14, 2011]. Simply
loaded with nonsense and evasion, leading to the court finding Mr. Refalo ‘not credible.’
Case Example
Q. "And this retrograde extrapolation model, has this been accepted in the scientific
community."
A. "There's been a lot of controversy on it, and it's because studies are performed differently
and there's problems with it."
* * * * *
Q. “There’s a plateau at some point, isn’t there.”
A. “Well, *** there is. It’s the peak, the highest point or blood alcohol concentration
reached, and that’s when absorption and elimination equal each other.”
Testimony of Jennifer Bray
State v. Wendt - Linn Co Case 09-122393 [February 18, 2011]
Ú Moral Of The Story Ú
When preparing to cross-examine State experts, get transcripts!
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Discovery - Crime Lab Testing & Reporting:
In cases involving evidence derived through retrograde extrapolation, it’s absolutely necessary to
obtain and analyze the test reports and all related notes from the crime lab.
Case Example
Q. “And if somebody is pre-peak, any kind of estimate that you would give would be
erroneous?
A. Yeah. I would have to possibly back out the drinks that were within a half an hour of
the time in question.
Q. So if you didn't know what time somebody stopped drinking, would that have any
effect on your ability to do a retrograde extrapolation?
A. Yes. We like to have them stop drinking within a half an hour of the time in question. If
they don't stop drinking within that time, but we do know how much they had to drink
then we just subtract that from the value of the estimate.”
* * * * *
Q. So if you have a known blood alcohol level, you can work backwards based on that
elimination rate?
A. Well, to be able to do this estimation I would have to assume that the person was
post-peak, meaning that they've already reached their maximum blood alcohol level
prior to the time in question.
* * * * *
Q. And if the person is pre-peak -- that means they have not metabolized all their alcohol
-- then there's no way to even calculate it; is that correct?
A. Yeah. We'd have to subtract out any drinks within a period of time, right before the
time in question. And so it would be a very, I guess, kind of raw estimate.
Testimony of Jennifer Bray
State v. Montgomery - Lake Co Case 08022CR93 [September 25, 2009]
Special Note to OCDLA Members - many Pond-Dwellers have/share copies of
transcripts from past trials upon request.
Rounding Errors:
When extrapolating a BAC from two (or more) samples to a prior point in time, the state
crime lab is required to adhere to analytical, computational and reporting standards specified by
administrative rule. Specifically, the lower limit of quantitation for this method is
administratively defined as 0.0100% (w/v). Source: Oregon State Police Forensic Services
Division Blood Alcohol Procedures Manual §10.0 - Reporting - Item 2: “Other Reporting
Considerations.”
Single-Point Analysis: Trending
A basic premise for application of retrograde extrapolation
is that, at the time of the breath test the defendant was in the
eliminative phase of his intoxication, when his/her BAC level
was decreasing. If a person is tested while in the absorption
phase their BAC at the time of the test will be higher than
their BAC while driving. If tested while in the elimination
phase their BAC at the time of the test could be lower than
while driving, depending on whether they had reached their
peak before or after the stop. Obviously, the greater the
length of time between the driving and the test, the greater
the potential variation between the two BACs. - Going Up or Down? -
Case Example - Crime Lab Worksheet Reveals
Sample One Taken @ 03:51 Sample Two Taken @ 04:21
Reported Test Values: 0.059 Reported Test Values: 0.052
Actual Test Values: 0.0585, 0.0589 Actual Test Values: 0.0527, 0.0522
+/-.0004 (rounds up to next higher value) +/-.0005 (rounds down)
The criminalist may attempt to use the difference between .059 and .052 (.007) as
a "dissipation" rate for ½ hr, and then "extrapolate" this to .014/hr as a dissipation
rate (.007 x 2).
Problem: The internal error rate is +/-.002%, which means .059 could be .057
and .052 could be .054, creating a potential difference of .003%. Based on this
difference, one could then assume that the "dissipation rate" is .006 (.003 x 2).
Cross-X: Administrative rule provides that the lower limit of quantitation is
.0100%. This means that any measured at values less than .010 (i.e. .010*%)
becomes unreliable. If the third digit is "reliable" (i.e. .058* and .052*) why
doesn't the lab report values less than .01? [Answer: because a value less than .010
is defined by administrative rule as ‘unreliable.’]. Source: OSP Forensic Services
Division “Blood Alcohol Procedures Manual” p. 27 (Rev. 6/7/2010).
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Plateau: Once in the blood, alcohol is carried throughout the body. The alcohol diffuses into
tissues and fluids according to their water content. During the absorption phase, the BAC of
arterial blood is greater than the BAC of venous blood. Arteries carry blood to a tissue, and veins
remove blood from the tissue. At equilibrium, where the tissue has absorbed a proportionate
quantity of alcohol, the BAC of arterial blood is equal to the BAC of venous blood. When this
occurs the rate of absorption is equal to the rate of elimination and hence the blood alcohol
concentration does not change. In some cases, a subject may develop a plateau, where the blood
alcohol level does not change for up to two hours. After two hours, the rate of elimination will
exceed the rate of absorption and the blood alcohol level will begin to decrease.
Filling in the “Variable Vacuum” on Cross Examination:
When challenging the State’s criminalist on his/her back-extrapolation calculations, often the
greatest opportunities come from identifying and pointing out which variables the criminologist
did not consider or considered using erroneous data [e.g. weight on ODL vs. actual weight, etc.],
and then having the defendant testify to fill in or correct the variable information during a
suppression hearing. Be sure to pin the criminologist down on what information was known
to/considered by the criminologist at the time s/he made her/his retrograde extrapolation
calculations, secure in the knowledge that the ‘new’ information disclosed by the defendant
during the suppression hearing cannot be used to support the criminologists’s opinion at trial (but
may be used for impeachment purposes). See ORS 135.037(4).
Note: the Intoxilyzer takes two readings from two separate breath samples provided
only about two minutes apart. For the purposes of drawing an alcohol concentration
curve (ACC) these two samples constitute only a single reading. An accurate ACC
would require many more points of data than the Intoxilyzer provides. Consequently,
the "single" reading provided by the machine does not provide enough information to
determine whether a person is in the absorption phase or the elimination phase at the
time of the breath test.
ORS 135.037(4): At the conclusion of the hearing and prior to trial the court shall
prepare and file an order setting forth all rulings of the court on issues raised under
subsection (2) of this section. The court shall further prepare and file a
memorandum of other matters agreed upon at the hearing. Except in a prosecution
of the defendant for perjury or false swearing, or impeachment of the
defendant, admissions made by the defendant or the attorney of the defendant
at the hearing may not be used against the defendant unless the admissions are
reduced to writing and signed by the defendant and the attorney.
7 Reasons to NOT Use Retrograde Extrapolation:
1. Not all blood and breath alcohol curves follow the Widmark patterns nor is the
elimination necessarily linear.
2. Alcohol absorption is not always complete within 60 to 90 minutes, as often claimed.
3. The peak alcohol concentration cannot be validly predicted or established in an individual
instance without frequent and timely measurements of alcohol concentrations.
4. It is not possible to establish whether an individual is in the absorption or elimination
phase, or to establish the mean overall rate of alcohol elimination from the blood or
breath, from the results of two consecutive blood or breath alcohol measurements,
however timed.
5. Significantly large short-term fluctuations occur in some subjects and result in marked
positive and negative departures from the alcohol concentration trend line.
6. Short-term, marked oscillation of the blood or breath alcohol concentration can occur at
various points of the curve, resulting in repeated excursions of the alcohol concentration
above and below a given concentration (such as 80 or 100 mg/dl) within a few minutes or
for hours.
7. No forensically-valid forward or backward extrapolation of blood or breath alcohol
concentrations is ordinarily possible for a given subject and occasion solely on the basis
of time and individual analysis results.
Making Use of Studies, Articles & Publications:
“Retrograde extrapolation applied to the data employing an assumed 0.15g/210 l/h yielded
a small but significant overestimate of the actual known BAC from breath testing.
Evidentiary analysis performed within two hours of driving will provide good estimates, and
certainly not overestimates, of the BAC existing at the time of driving and it appears that
extrapolation may be unwarranted in these cases.”
Comparing Roadside With Subsequent Breath Alcohol Analysis
And Their Relevance To the Issue Of Retrograde Extrapolation,
Forensic Science International, 57 (1992) 193 - 201.
~ ~ ~ ~ ~
“Back extrapolation determinations of blood alcohol levels based on a single rate of decrease in
concentration vs. a non-linear rate of decrease in concentration (particularly if low) must often
yield estimates bordering on wild guesses.”
The Metabolism and Pharmocokinetics of Alcohol in Man,
J. Forens. Sci Soc (1977), 17, 49.
~ ~ ~ ~ ~
“The simple Widmark calculation used by many experts results in a higher BAC than any of the
other methods, whereas the other methods tend to agree with each other and not with Widmark.
The primary reason for the elevated numbers obtained when using the Widmark ‘r’ value
is that the other methods calculate ‘r’ based on measured parameters rather than relying
on the average value obtained from a small group of individuals in 1932. “
The Estimation of Blood Alcohol Concentration Widmark Revisited,
Forensic Sci. Med. Pathol.: 3:1:33
~ ~ ~ ~ ~
“A trend-line curve is markedly inappropriate or useless for attempts to engage in retrograde
extrapolation, for, among others, three main reasons: (1) lack of knowledge about the timing of
the alcohol consumption peak; (2) ignorance about the mathematical characteristics (e.g.
linear, pseudo-linear, exponential); and the mean rate of change in the individual’s blood or
breath alcohol elimination curve; and (3) unpredictable irregularities in the curve, especially
short-term fluctuations from the best-fit trend line of the blood or breach alcohol curve.”
“Most alcohol pharmacokinetics parameters are subject to a wide inter-subject variability, as
exemplified by peak alcohol concentrations reached on ingestion of identical weight-adjusted
doses, time to peak after end of drinking and rate of alcohol elimination from the blood. This
great biological inter-subject variability, when combines with sex-, age and time-related
differences, makes the blood alcohol on information in widely distributed alcohol
consumption nomgrams and tables based on mean data inappropriate as a guide for the
drinking behaviors of individuals.”
“Breath and blood alcohol time curves are subject to short-term fluctuations from the
trend line and other irregularities, and often do not follow the typical Widmark pattern.”
Absorption, Distribution and Elimination of Alcohol: Highway
Safety Aspects. Kurt Dubowski, PhD, Journal of Studies on
Alcohol, Supplement No. 10, July 1985 pp 103, 105 & 106.
~ ~ ~ ~ ~
“..... the practice of making a back estimation of a person’s BAC is inevitably a
controversial issue.”
Karch - Drug Abuse Handbook,
Chap. 13.2 by A.W. Jones & B. Logan
~ ~ ~ ~ ~
“Uncertainties surrounding the absorption kinetics of alcohol make it difficult for a
forensic expert witness to state unequivocally whether the BAC was rising or falling at the
time of the road-traffic accident.”
Alcohol, Drugs & Driving 1992 - Physiological Aspects
of Breath-Alcohol Measurements by A.W. Jones
“No forensically-valid forward or backward extrapolation of blood or breath alcohol
concentrations is ordinarily possible in a given subject and occasion solely on the basis of
time and individual analysis results.”
Absorption, Distribution and Elimination of Alcohol: Highway
Safety Aspects. Kurt Dubowski, PhD, Journal of Studies on
Alcohol, Supplement No. 10, July 1985 pp 103, 106.
~ ~ ~ ~ ~
Retrograde extrapolation is performed when a blood or a breath alcohol concentration is used in
conjunction with a drinking history to estimate an alcohol concentration at some time before the
subject provided the specimen. Often this time is the time of observed driving, the officer’s stop
or the time of the crash. This estimation cannot be simply done by adding back for the
expected elimination using an average rate.
Lecture at the Borkenstein Alcohol Course: Pharmacology
of Alcohol-Extrapolations. Dr. Robert Forney
Oregon Cases Addressing Retrograde Extrapolation:
State v. Eumana-Moranchel, 352 Or 1 (2012) (Retrograde extrapolation analysis is based on and
derived from a chemical test [breath/blood/urine] and that * * * the retrograde extrapolation
analysis, applied to the chemical test result, explains that the chemical test “shows” that
defendant drove with a BAC of .08 percent or more per ORS 813.010(1)).
http://www.publications.ojd.state.or.us/docs/S059602.pdf
State v. Whitmore, 257 Or App 664 (2013) When the State offers an expert on blood alcohol
dissipation and retrograde extrapolation, it must first make a foundational showing that the
expert’s methods were scientifically valid pursuant to Brown/O’Key. Here, the expert had a
background in forensic science and her knowledge of blood alcohol chemistry was based on the
literature in the field. Because she was offering a scientific opinion, the foundational showing
needed to be made. http://www.publications.ojd.state.or.us/docs/A146430.pdf
State v. Montgomery, 256 Or App 222 (2013) (Court erred in denying motion to exclude DRE
Officer’s testimony relating to rate of dissipation of alcohol, finding that the State failed to lay a
scientific foundation for evidence involving the precise rate of dissipation of alcohol (with a
lesson to defense counsel)). http://www.publications.ojd.state.or.us/docs/A144361.pdf
State v. Ohotto Or App (February 12, 2014) (the court erred when admitting the testimony
of a deputy estimating the ‘likely’ number of drinks required for defendant to reach a .17 BAC,’
because the State failed to establish a sufficient foundation for expertise in the field through an
assessment of the deputy's particular qualifications.
http://www.publications.ojd.state.or.us/docs/A148725.pdf
Other Jurisdictions Addressing Retrograde Extrapolation:
A list of case citations to other jurisdictions is included in the Supplemental Materials.
Judicial Words of Wisdom:
“ * * * if retrograde extrapolation standing alone is sufficient to establish a
violation of the statute, the statute risks over inclusivity, because there is no limit
to how far the State may extrapolate to secure a conviction. The majority's
interpretation would permit the State to prove through retrograde extrapolation not
only that a person with a .07 percent BAC was over .08 percent one hour earlier,
but also that a person with a .01 percent BAC was over .08 percent eight hours
earlier. The scientific principles supporting retrograde extrapolation have not
advanced to such a state today—and certainly had not in 1975 when the
legislature first enacted this statute—to permit such a conviction beyond a
reasonable doubt.
The plain meaning of the text of the statute also supports my conclusion that the
legislature had no intention of including retrograde extrapolation as a “chemical
analysis” under paragraph (a). The legislature required that a BAC of .08 percent
or more must be “shown by chemical analysis of the breath or blood of the
person” in order to support a determination that a person has committed the
offense of driving under the influence under ORS 813.010(1)(a). The legislature
did not provide that a BAC of less than .08 percent, as shown by chemical
analysis, could somehow be rehabilitated or explained away by expert testimony
or any other circumstantial evidence under paragraph (a). The terms the
legislature used in paragraph (a) plainly require that a chemical analysis made
under ORS 813.100, ORS 813.140, or ORS 813.150 must itself show that a person
has a BAC of .08 or greater. That reading of the text is well supported by the
applicable definitions of the terms the legislature used in the statute and by the
general rules of grammatical construction that inform our understanding of
statutory terms.”
De Muniz, J, joined by Durham and Walters, dissenting opinion in State v. Eumana-Moranchel,
352 Or 1, 15 - 16, 277 P3d 549 (2012) (a definate “Must-Read”).
Words of Advice -
1. Do your homework - be the most informed person in the courtroom on your issue(s)
2. Consult with an expert - listen to/learn from your expert
3. Use an expert witness at trial to explain and provide an evidentiary foundation for your
challenges. Prepare to co-op the State’s expert(s)
4. Evaluate and consider the preparation and competency of your prosecutor in your
pre-trial/trial strategy planning/decisions
5. Educate your trial judge
6. Get transcripts of prior testimony for State experts
Read/consider the issues addressed by the National Research Council of the National Academies
in Strengthening Forensic Science in the United States: A Path Forward. Washington, DC: The
National Academies Press, (2009) http://www.nap.edu/openbook.php?record_id=12589.
Additional Challenges(?):
ORS 813.010 - Retrograde Extrapolation is not a “chemical analysis”
(1) A person commits the offense of driving while under the influence of intoxicants if the
person drives a vehicle while the person:
(a) Has 0.08 percent or more by weight of alcohol in the blood of the person as shown
by chemical analysis of the breath or blood of the person made under ORS
813.100 (implied consent to breath or blood test), 813.140 (chemical test with
consent) or 813.150 (chemical test at request of arrested person);
(b) Is under the influence of intoxicating liquor, a controlled substance or an inhalant;
or,
(c) Is under the influence of any combination of intoxicating liquor, an inhalant and a
controlled substance.
Challenge Opportunity? - In order to submit evidence of a defendant’s blood-alcohol content, the
State must “show by chemical analysis” that the defendant’s blood-alcohol content was .08 or
higher. Perhaps not. See State v. Eumana-Moranchel, 352 Or 1, 9, 277 P3d 549 (2012): Read
Justice De Muniz’ dissent for a lengthy discussion and potential challenge opportunities to
retrograde extrapolation of a defendant’s blood-alcohol content.
Acknowledgments
Special thanks are given to OCDLA Member Kenn Meneely of Willamette Valley Forensics, LLC
for portions of his trial materials used in this presentation, as well as his knowledge (& patience)
assisting and educating numerous defense counsel on retrograde extrapolation.
Thanks also go out to OCDLA member Russell Barnett (“RB3") for his inspired tennis-ball
metaphor (and cross-examination) from State v. Zamede, Clackamas Co. Circuit Court Case
CR1113196 (May 17, 2012).
Thanks also go out to OCDLA member Kevin Sali for his contributions to and materials used
from OCDLA’s Library of Defense.
Thanks also to David R. for his confidence and investment supporting this author’s education
and application of the science of retrograde extrapolation, as well as for his extraordinary
commitment to the pursuit of Science and Justice.
Finally, immeasurable thanks go out to the many OCDLA members who regularly swim the Pond
and contribute their experience, wisdom and support for the cause of defending others.
* * * Supplemental Materials Follow * * *
Presentation Materials [Final]
Presentation Materials [Final]
Presentation Materials [Final]
Other Jurisdictions Addressing Retrograde Extrapolation
Presentation Materials [Final]
Presentation Materials [Final]
Presentation Materials [Final]
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Dubowski, Absorption, Distribution and Elimination of Alcohol: Highway Safety Aspects Journal1
of Studies of Alcohol (1985); Mason and Dubowski, Breath Alcohol Analysis: Uses, Methods, and Some
Forensic Problems – Review and Opinion, 21 Journal of Forensic Sciences 9 (1976); Simpson,
Medicolegal Alcohol Determination: Implications and Consequences of Irregularities in Blood Alcohol
Page 1 – MOTION IN LIMINE TO EXCLUDE EVIDENCE OF RETROGRADE EXTRAPOLATION WITHOUT
PROPER FOUNDATION
LAW OFFICES OF BRIAN COX
142 West 8 Avenueth
Eugene, Oregon 97401
Telephone: (541) 683-7151 † Facsimile: (541) 485-7742
coxandassociates@coxassociates.info
IN THE CIRCUIT COURT OF THE STATE OF OREGON
FOR THE COUNTY OF NAUGHT
STATE OF OREGON, ) Case No. XX-XXXXX
)
Plaintiff, ) MOTION IN LIMINE TO EXCLUDE
) EVIDENCE OF RETROGRADE
v. ) EXTRAPOLATION WITHOUT
) PROPER FOUNDATION
MISS MISTY ACCUSED, )
) ORAL ARGUMENT REQUESTED
Defendant. )
Motion
This motion seeks to require the State to provide an adequate Brown / O’Key / Daubert /
Kuhmo foundation prior to the admissibility of any evidence relating to retrograde extrapolation,
or in the absence of adequate foundation, to object to admission of any such information and/or
evidence relating to retrograde extrapolation pursuant to OEC 401, 702 & 403.
Statement of Facts
Miss Accused was involved in a collision between two motor vehicles on January 1 ,st
2014. Blood and urine samples were taken at the hospital after the accident. It is expected that
the State will attempt to question an un-designated Expert Witness (Criminalist) in a manner
designed to extract testimony relating to Miss Accused’s projected/average blood-alcohol level
at the time of driving derived from information obtained from these samples. This proffered
analytical approach is known as “retrograde extrapolation” and is not considered to be reliable or
generally accepted by a consensus of scientists competent in forensic alcohol analysis. It is1
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Concentrations vs Time Curves, 16 Journal of Analytical Toxicology (1992).
Winek and Murphy, The Rate and Kinetic Order of Ethanol Elimination, 29 Forensic Science2
International 159 (1984); Jones, Disappearance Rate of Ethanol From the Blood of Human Subjects:
Implications in Forensic Toxicology, 38 Journal of Forensics 103 (1993).
3 Nat'l Inst. on Alcohol Abuse & Alcoholism, Alcohol Alert, "Alcohol Metabolism," No. 35 (Jan.
1997).
Jennifer Pariser, Note: In Vino Veritas: The Truth About Blood Alcohol Presumptions in State4
Drunk Driving Law, 64 N.Y.U.L. Rev. 141, 146 (1989), citing S. Brent & S. Stiller, Handling Drunk
Driving Cases, § 4:2 (1985); Edward Fitzgerald & Dr. David Hume, The Single Chemical Test for
Intoxication: A Challenge to Admissibility, 66 Mass. L. Rev. 23, 28 (1981).
Pariser, 64 N.Y.U.L. Rev. at 147, citing 2 R. Erwin, Defense of Drunk Driving Cases Criminal /5
Civil §15.04[1][b][i], at 15 (3d ed. 1988); Rodney Gullberg, Variation in Blood Alcohol Concentration
Following the Last Drink, 10 J. of Police Science & Admin. 289 (1982); Alan Jones et al., Peak Blood-
Ethanol Concentration and the Time of Its Occurrence After Rapid Drinking on an Empty Stomach, 36 J.
of Forensic Science 376, 381 (1991).
6 NIAAA Alcohol Alert, "Alcohol Metabolism," No. 35 (Jan. 1997).
7 Y. Al-Lanqawi et al., Ethanol Kinetics: Extent of Error in Back Extrapolation Procedures, 34
British J. of Clinical Pharmacology 316, 320 (1992).
Page 2 – MOTION IN LIMINE TO EXCLUDE EVIDENCE OF RETROGRADE EXTRAPOLATION WITHOUT
PROPER FOUNDATION
LAW OFFICES OF BRIAN COX
142 West 8 Avenueth
Eugene, Oregon 97401
Telephone: (541) 683-7151 † Facsimile: (541) 485-7742
coxandassociates@coxassociates.info
further expected that the Criminalist will base his/her testimony on “averages” that do not take
into consideration the scientific fact that absorption and elimination rates are highly variable and
are effected by a myriad of factors, most commonly including weight, gender, physical
condition, metabolic rate, time of day, when, what, and how much was last eaten, when, what,
and how much and how the subject drank, whether any medications were taken or not taken,
emotional state, and whether the subject is an alcoholic.2
Retrograde extrapolation is the computation back in time of the blood-alcohol level - that
is, the estimation of the level at the time of driving based on a test result from some later time.
As alcohol is consumed, it passes from the stomach and intestines into the blood, a process
referred to as absorption. When the alcohol reaches the brain and nervous system, the3
characteristic signs of intoxication begin to show. The length of time necessary for the alcohol4
to be absorbed depends on a variety of factors, including the presence and type of food in the
stomach, the person's gender, the person's weight, the person's age, the person's mental state,5 6 7 8 9
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Ibid.8
Jones et al., 36 J. of Forensic Science at 381.9
Ibid.10
11 Ibid.
Gullberg, 10 J. of Police Science & Admin. at 289.12
13 Ibid.
14 All of Widmark's work was done on subjects who drank a metered amount of alcohol on an empty
stomach. Id. at 3-2 et seq. In the original test group of 30 subjects, only 3 (10%) tested in the absorption
range of 0.65 and 0.70, 19 (63%) tested under 0.65 and 8 (27%) tested over 0.65. The subjects' elimination
rates varied from 0.006 to 0.04 with most being widely distributed between 0.010 and 0.020.
Pariser, 64 N.Y.U.L. Rev. at 152, citing W. Frajola, Defending Drinking Drivers 16.1 (1985).15
Page 3 – MOTION IN LIMINE TO EXCLUDE EVIDENCE OF RETROGRADE EXTRAPOLATION WITHOUT
PROPER FOUNDATION
LAW OFFICES OF BRIAN COX
142 West 8 Avenueth
Eugene, Oregon 97401
Telephone: (541) 683-7151 † Facsimile: (541) 485-7742
coxandassociates@coxassociates.info
the drinking pattern, the type of beverage consumed, the amount consumed, and the time10 11 12
period of alcohol consumption. At some point after drinking has ceased, the person's BAC will13
reach a peak. After the peak, the BAC will begin to fall as alcohol is eliminated from the
person's body. The body eliminates alcohol through the liver at a slow but consistent rate.
In 1932, Swedish chemist E.M.P. Widmark first calculated absorption and elimination14
rates in the body, and his work still represents the benchmark for other scientists' studies today.
Widmark created what we know today as the "BAC curve," which represents the rise and fall of
an individual's BAC as his body absorbs and eliminates alcohol. A reading from a single breath
test will not reflect where the person is on his BAC curve. In other words, it will not indicate
whether the person is in the absorption phase, at his peak, or in the elimination phase.15
If a driver is tested while in the absorption phase, his BAC at the time of the test will be
higher than his BAC while driving. If tested while in the elimination phase, his BAC at the time
of the test could be lower than while driving, depending on whether he had reached his peak
before or after he was stopped. The greater the length of time between the driving and the test,
/////
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See, Dubwoski, fn. 1, supra.16
297 Or 404, 687 P2d 751 (1984).17
State v. Brown, 297 Or at 417.18
State v. O’Key, 321 Or 285, 302 - 303, 899 P2d 663 (1995).19
Page 4 – MOTION IN LIMINE TO EXCLUDE EVIDENCE OF RETROGRADE EXTRAPOLATION WITHOUT
PROPER FOUNDATION
LAW OFFICES OF BRIAN COX
142 West 8 Avenueth
Eugene, Oregon 97401
Telephone: (541) 683-7151 † Facsimile: (541) 485-7742
coxandassociates@coxassociates.info
the greater the potential variation between the two BAC levels.16
Even if retrograde extrapolation were scientifically valid, the state is unable to provide a
sufficient factual foundation for it to be useful in this case. There is insufficient knowledge as to
the time and quantity of drinking as well as other physiological factors which would have to be
accounted for, in order to even begin to apply any retrograde extrapolation.
1. The Retrograde Extrapolation Used in this Case must Be Judged under the Brown /
O’Key Standard of Admissibility
In 1984 the Oregon Supreme Court reached a decision in State v. Brown regarding general17
principlesofadmissibilityofexperttestimonybasedonnewscientifictechniques.InStatev. Brown,
the court required seven factors to consider when deciding the admissibility of evidence based on
scientific techniques; those being:
(1) The technique’s general acceptance in the filed;
(2) The expert’s qualifications and stature;
(3) The use which has been made of the technique;
(4) The potential rate of error;
(5) The existence of specialized literature;
(6) The novelty of the invention; and,
(7) The extent to which the technique relies on the subjective interpretation of
the expert.18
The court further illuminated this issue in State v. O’Key as follows:19
Thus, under the Daubert approach, a trial court, faced with a proffer of expert
scientific testimony, must determine at the outset, pursuant to FRE 104(a), whether
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Daubert v. Merrill Dow Pharmaceuticals, Inc. 509 U.S. 579 (1993); See also Kumho Tire Co.,20
Ltd. v. Carmichael (1999) U.S., 119 S. Ct. 1167.
Kumho Tire at 1175 (emphasis added).21
Ibid, at 1176.22
Page 5 – MOTION IN LIMINE TO EXCLUDE EVIDENCE OF RETROGRADE EXTRAPOLATION WITHOUT
PROPER FOUNDATION
LAW OFFICES OF BRIAN COX
142 West 8 Avenueth
Eugene, Oregon 97401
Telephone: (541) 683-7151 † Facsimile: (541) 485-7742
coxandassociates@coxassociates.info
the proposed evidence is based on scientifically valid principles and is pertinent to
the issue to which it is directed. 509 U.S. at ---- n. 10, 113 S. Ct. at 2796 n. 10, 125
L. Ed.2d at 482 n. 10. The proponent of the evidence has the burden of establishing
those matters by a preponderance of the evidence. Id.
A. Use of expert testimony guided by Oregon Evidence Code §§ 702 & 703.
Admissibility of scientific evidence is determined by the court pretrial. Such an evaluation
of the admissibility of the opinion has been described as the “gate keeping” function of the trial
court. This entails a preliminary assessment of whether the reasoning or methodology underlying
the testimony is scientifically valid and of whether that reasoning or methodology properly can be
applied to the facts at issue.20
In Kumho, supra, the United States Supreme Court analyzed addressed the analysis of the
“gate keeping” role Federal Rules of Evidence as determined by Daubert, supra, its analysis of the
“gate keeping” role under any standard, including the standard required under Brown and O’Key
equally applies. The Court referred to this position by stating that “the gate keeping inquiry” of
Daubert, supra, is applicable when “the relevant reliability concerns may focus upon personal
knowledge or experience” of the witness. This is true because “some of Daubert’s questions can21
help to evaluate the reliability even of experience-based testimony.”22
2. The Retrograde Extrapolation Used in this Case Do Not Pass Brown
In State v. O’Key, the Supreme Court adopted the Daubert model and also held that the
burden of showing general acceptance lies with the proponent of the evidence to show a “scientific
consensus.”TheCourtnotedthat “ifafairreviewoftheliteraturedisclosesthatscientistssignificant
in either number or expertise publicly oppose the technique as unreliable, then the court may safely
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State v. O’Key, at 55 - 56.23
Ring v. Taylor, 141 Ariz. 56, 69, 685 P.2d 121, 134 n.6 (Ariz. Ct. App. 1984)(Comment made in a24
footnote without citation to further authority).
Page 6 – MOTION IN LIMINE TO EXCLUDE EVIDENCE OF RETROGRADE EXTRAPOLATION WITHOUT
PROPER FOUNDATION
LAW OFFICES OF BRIAN COX
142 West 8 Avenueth
Eugene, Oregon 97401
Telephone: (541) 683-7151 † Facsimile: (541) 485-7742
coxandassociates@coxassociates.info
conclude there is no such consensus at the present time.”23
In Mata v State of Texas, 46 SW 3d 902 (Tex. Crim. App. 2001), the Court of Criminal
Appeals overturned a conviction of a drunk driving defendant who had a 0.19% blood alcohol level
measured by a breath test because of the improper introduction of unreliable evidence of retrograde
extrapolation. The opinion of the Court carefully analyzed the state of current scientific literature
in the area of retrograde extrapolation and detailed the opinions of a number of leading experts in
the field. In addition, the Court analyzed case law from other states in the area and concluded that
Arizona is the sole state finding that retrograde extrapolation has “achieved general acceptance in
the scientific field.” The State of Alabama disagreed in Smith v. Tuscaloosa,601 So.2d 1136, 114024
(Ala. Crim. App. 1992) quoting E. Abbott, "One for the Road" - The Reliability of Retrograde
Extrapolation and the Implications for Vermont Statutes, 16 Vt.L.Rev. 395, 397 (1991):
“[C]areful analysis of these studies indicates that retrograde extrapolation is an
unreliable method of determining a defendant's condition at the time of operation.
The inadequacies of retrograde extrapolation extend beyond mere technical
inaccuracies to problems which are inherent in the basic premises and calculations
of this technique. These inadequacies render retrograde extrapolation inherently
untrustworthy and therefore inappropriate for use as evidence to convict drunk
drivers.”
It is therefore clear from the analysis adopted byvirtually all states that retrograde extrapolation has
not received the state of general acceptance in the relevant scientific community of forensic
toxicology in general. Furthermore, it is universally accepted that any attempt at extrapolation
without the necessary foundational information to limit the variations of the Widmark formula is
“junk science.” In the Concurring Opinion in Mata v. State of Texas, Justice Johnson highlighted
the difficulty in accurately trying to predict a blood alcohol level at a time earlier than measurement
and pointed out:
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Page 7 – MOTION IN LIMINE TO EXCLUDE EVIDENCE OF RETROGRADE EXTRAPOLATION WITHOUT
PROPER FOUNDATION
LAW OFFICES OF BRIAN COX
142 West 8 Avenueth
Eugene, Oregon 97401
Telephone: (541) 683-7151 † Facsimile: (541) 485-7742
coxandassociates@coxassociates.info
“A simple mathematical formula for the number of possible combinations of
variables is 2 to the power equal to the number of variables, e.g., 5 variables
indicates 25, producing 32 possible results. Noted above are at least twenty
variables. The number of possible results is thus 220, or 1,048,576. However, this
simple equation assumes that each variable has only two values and does not
consider any possible interactions between variables. The general equation is the
number of possible values, "m," raised to the power of the number of variables, "n,"
or mn. Assuming an average of 5 values per variable and twenty variables, the
number of possibleresults, 520, is 24,414,062. Each variable in the BAC calculation
has many possible values. Many of the variables have a possibility of interacting
with each other and further complicating the matter. Even assuming a relatively
small number of possible values, the number of possible results increases
exponentially and quickly becomes mind-boggling.
Conclusion
The standard for admissibility of evidence based on new scientific techniques first
propounded in Brown, and left unchanged by Daubert, is applicable to retrograde extrapolation.
Pursuant to the California Evidence Code and the recent decision of the United States Supreme
Court in Kumho, the Brown standard is applicable to testimony based on training and experience
as well as more traditional “scientific” knowledge. Under that standard, evidence of retrograde
extrapolation is inadmissible until shown to be in conformance with Brown, supra., which is
difficult and particularly-unlikelyunder the facts of this case. The retrograde extrapolation tests and
calculations used in this case do not and cannot be shown to meet this standards for reliability
required in order to provide adequate evidentiary foundation for admission of such information at
trial, and therefore it should and must be excluded.
Dated this 7 day of March, 2014.th
COX & ASSOCIATES, LLC
By:
Brian D. Cox, OSB 902405
Of Attorneys for Miss Accused
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Page 8 – MOTION IN LIMINE TO EXCLUDE EVIDENCE OF RETROGRADE EXTRAPOLATION WITHOUT
PROPER FOUNDATION
LAW OFFICES OF BRIAN COX
142 West 8 Avenueth
Eugene, Oregon 97401
Telephone: (541) 683-7151 † Facsimile: (541) 485-7742
coxandassociates@coxassociates.info
Summary of Exhibits
[Full Articles/Studies to Be Offered During Hearing]
Relating to Timed Effect of Marijuana Consumption
Exhibit 1: Redwood Toxicology Laboratory Reference Guide
Summary: Once in the blood, THC is bound to blood proteins and carried throughout the
body where it is either absorbed into body tissues or transformed by the liver into
the water soluble metabolites 11-hyroxy-THC and carboxy-THC. These water
soluble metabolites are readily excreted into the urine, with the inactive
metabolite carboxy-THC being the predominant metabolite detected.
Initially, TCH is quickly absorbed into the blood stream where it is carried to the
liver and metabolized. Because THC tends to be stored in fatty tissues, it
accumulates faster than it can be eliminated in chronic repetitive smokers. This
leads to extended retention of THC which is then eliminated from the body
at a relatively constant rate with an average elimination half-life being
estimated at 18-30 hours. Urinary concentrations of THC are very difficult to
interpret due to variables such as dosage of the THC ingested, frequency of use,
timing of urine collection relative to last exposure to marijuana, rate of release of
stored cannabinoids in adipose tissue, and an individual’s hydration rate.
Therefore, the detection of THC metabolites in urine is only an indication of
past marijuana use and is not related to the degree of intoxication or
impairment. [Marijuana (TCH) Drug Information, p. 43].
Exhibit 2: Drug Evaluation And Classification Training Program - The Drug Recognition
Expert School. US Department of Transportation, Transportation Safety Institute
National Highway Traffic Safety Administration January 2007 Edition.
Summary: Persons begin to feel and exhibit marijuana’s effects within 8-9 seconds after
inhaling the smoke. The effects usually reach their peak within 10-30 minutes,
and the effects generally continue for 2-3 hours. There are studies that indicate
that the user may be impaired long after the euphoric effects have ceased.
It is important to understand that some blood and urine tests may continue
to disclose evidence of the use of marijuana long after the effects of
marijuana have dissipated. That is because certain chemical tests do not seek to
find THC itsef, but instead look for metabolites of THC, or chemical by-products.
It can take as long as four hours for THC to appear in the urine in concentrations
sufficient to trigger an immunoassay (50 ng/mL) following smoking. Some blood
tests may disclose marijuana use for at least three days after smoking. Some
urine test may indicate the presence of THC metabolites for 28-45 days.
There are two important metabolites of THC. One of the metabolites is Hyroxy
THC; this causes the user to feel euphoric so they are aware of the effects.
Hydroxy TCH usually is eliminated from the blood plasma within six hours. The
other important metabolite if Carboxy THC. There is no evidence at this time
that the metabolite is psychoactive. Carboxy TCH may be found in the blood
plasma for several days following marijuana use. Supra at XX1-2 - XX1-3.
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Page 9 – MOTION IN LIMINE TO EXCLUDE EVIDENCE OF RETROGRADE EXTRAPOLATION WITHOUT
PROPER FOUNDATION
LAW OFFICES OF BRIAN COX
142 West 8 Avenueth
Eugene, Oregon 97401
Telephone: (541) 683-7151 † Facsimile: (541) 485-7742
coxandassociates@coxassociates.info
Citations to Additional Studies:
“It is not possible to conclude anything about a driver’s impairment on the basis
of his or her plasma concentrations of … THC-COOH determined in a single
sample.” U.S. Department of Transportation Marijuana and Actual Driving
Performance November 1993. p. 108.
“The presence of THC–COOH thus does not necessarily imply recent use of
cannabis or impairment. … [T]his metabolite, THC–COOH, can be assessed in
body fluids for hours and days and is not a reliable indication of recent cannabis
use or impairment. … [T]hese data indicate that recent cannabis use may
increase crash risk, whereas, past use of cannabis as determined by the presence
of THC–COOH in drivers does not.” Ramaekers et al. 2004. Dose related risk of
motor vehicle crashes after cannabis use. Drug and Alcohol Dependence 73:
109-119.
“[T]here is little scientific evidence to show that the detection of … THC-COOH
in bodily fluids can be taken as proof of impairment in any circumstance.”
Ramaekers et al. 2006. Cognition and motor control as a function of delta-9-THC
concentration in serum and oral fluid: limits of impairment. Drug and Alcohol
Dependence 8: 114-122.
“Quantitation of THC-COOH can neither accurately predict the time of last
cannabis use nor suggest any relationship between urine concentration and
psychomotor performance.” Musshoff and Burkhard. 2006. Review of biologic
matrices as indicators of recent or ongoing cannabis use. Therapeutic Drug
Monitor 28: 155-163.
Relating to Retrograde Extrapolation of Blood Alcohol Content
Exhibit 3: Comparing Roadside With Subsequent Breath Alcohol Analysis And Their
Relevance To the Issue Of Retrograde Extrapolation, Forensic Science
International, 57 (1992) 193 - 201.
Summary: Retrograde extrapolation applied to the data employing an assumed 0.15g/210 l/h
yielded a small but significant overestimate of the actual known BAC from
breath testing. Evidentiary analysis performed within two hours of driving will
provide good estimates and certainly not overestimates, of the BAC existing at
the time of driving and it appears that extrapolation may be unwarranted in these
cases.
Exhibit 4: The Metabolism and Pharmocokinetics of Alcohol in Man, J. Forens. Sci Soc
(1977), 17, 49
Summary: Back extrapolation determinations of blood alcohol levels based on a single rate
of decrease in concentration vs. a non-linear rate of decrease in concentration
(particularly if low) must often yield estimates bordering on wild guesses.
Exhibit 5: The Estimation of Blood Alcohol Concentration Widmark Revisted, Forensic Sci.
Med. Pathol.: 3:1:33
1
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Page 10 – MOTION IN LIMINE TO EXCLUDE EVIDENCE OF RETROGRADE EXTRAPOLATION WITHOUT
PROPER FOUNDATION
LAW OFFICES OF BRIAN COX
142 West 8 Avenueth
Eugene, Oregon 97401
Telephone: (541) 683-7151 † Facsimile: (541) 485-7742
coxandassociates@coxassociates.info
Summary: The simple Widmark calculation used by many experts results in a higher
BAC than any of the other methods, whereas the other methods tend to agree
with each other and not with Widmark. The primary reason for the elevated
numbers obtained when using the Widmark ‘r’ value is that the other methods
calculate ‘r’ based on measure parameters rather than relying on the
average value obtained from a small group of individuals in 1932.
Exhibit 6: Absorption, Distribution and Elimination of Alcohol: Highway Safety Aspects.
Kurt Dubowski, PhD, Journal of Studies on Alcohol, Supplement No. 10, July
1985
Summary: A trend-line curve is markedly inappropriate or useless for attempts to engage in
retrograde extrapolation, for, among others, three main reasons: (1) lack of
knowledge about the timing of the alcohol consumption peak; (2) ignorance about
the mathematical characteristics (e.g. linear, pseudo-linear, exponential); and the
mean rate of change in the individual’s blood or breath alcohol elimination curve;
and (3) unpredictable irregularities in the curve, especially short-term fluctuations
from the best-fit trend line of the blood or breach alcohol curve. Supra @ 103.
Most alcohol pharmocokinetics parameters are subject to a wide inter-subject
variability, as exemplified by peak alcohol concentrations reached on ingestion of
identical weight-adjusted doses, time to peak after end of drinking and rate of
alcohol elimination from the blood. This great biological inter-subject variability,
when combines with sex-, age and time-related differences, makes the blood
alcohol on information in widely distributed alcohol consumption nomgrams and
tables based on mean data inappropriate as a guide for the drinking behaviors of
individuals. Supra @ 105.
Breath and blood alcohol time curves are subject to short-term fluctuations from
the trend line and other irregularities, and often do not follow the typical
Widmark pattern. Supra @ 106.
=====================================================================
Certificate of Service
I certify that on this date I served the foregoing Motion in Limine to Exclude Evidence of
Retrograde Extrapolation Without Proper Foundation upon the State by causing a true and
complete copy of the same to be transmitted by facsimile to:
Darwin Wuzright Facsimile Number - (123) 456-7891
Naught County District Attorneys Office
Dated this 7 day of March, 2010.th
COX & ASSOCIATES, LLC
By:
Brian D. Cox, OSB 902405
Of Attorneys for Miss Accused

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Presentation Materials [Final]

  • 1. Counting Backwards: Winning Methods with the Widmark & Retrograde Extrapolation Presented by Brian Cox Defending The Modern DUII OCDLA - Eugene - March 7 - 8, 2014 - or - ??? What Is Retrograde Extrapolation? Retrograde extrapolation is the term for a scientific analysis looking at someone's blood-alcohol level at the time of testing and calculating the alcohol level at a prior point in time. In other words, retrograde extrapolation is simply mathematics - with many built-in assumptions. Understanding the strengths and weaknesses of multiplying an elimination rate by a time factor, however, requires knowledge of toxicology, pharmacology, physiology, metabolism and related fields, making it the province of expert witnesses. Disagreements between experts about the variables and correct elimination rates to be applied go to the weight of the evidence, as do the differences in the experts’ credentials. Who the Heck Is Widmark & Why Do We Care? Swedish physician E.M.P. Widmark is credited with doing much of the foundational research regarding alcohol kinetics in the human body during the early part of the 20 century. In addition,th he developed an algebraic equation allowing one to estimate any one of six variables given the other five in order to calculate blood alcohol concentration. According to Widmark’s equation, the amount of alcohol consumed (A) is a function of these several variables. L L L The Widmark Formula can be expressed in a long (set out at the end of the materials) or a short form. Many (so called) expert witnesses attempt to only use the short form, which can lead to inaccuracies in the calculation; even the long form of Widmark's formula is not 100% accurate. The Basic Widmark Formula is as follows: % BAC = (A x 5.14 / W x r) - .015 x H Note: All of Widmark's work was done on subjects who drank a metered amount of alcohol on an empty stomach. In the original test group of 30 subjects, only 3 (10%) tested in the absorption range of 0.65 and 0.70, 19 (63%) tested under 0.65, and 8 (27%) tested over 0.65. The subjects' elimination rates varied from 0.006 to 0.04 with most being widely distributed between 0.010 and 0.020.
  • 2. "A" is the total number of ounces of alcohol ingested by the individual starting at the first drink. "5.14" is a mathematical conversion factor (.823 x 100/16) used to convert liquid ounces to regular weighted ounces, with the "100" used to convert the final value to a percentage, and lastly, "16" is used to convert pounds to ounces. "W" stands for the weight of the individual consuming the alcohol, while "r" is the distribution ratio for alcohol through the body. For men, "r" stands for 0.73, while for women the value is 0.66. “.015" is the ‘average’ used to represent the alcohol elimination (dissipation) rate. A range from 0.010 to 0.025% can appropriately be used. Lastly, "H" is the period of time, in hours, that alcohol was eliminated from the body -- in other words, how quickly the alcohol finished going though the bloodstream and then was processed by the liver, thereby losing the potent effect of the alcohol itself. Typically, "H" is equal to the time between the first drink and the time the BAC calculations are being made (typically the time of driving). Key to BAC levels and the Widmark Formula is the idea that all people share the same or very similar parameters for alcohol absorption and elimination through the body. This includes distribution of alcohol through the bloodstream, meaning how long it takes a drink to work its way through your body before the BAC reading will reach its true mark. While rough estimates place people at the same values for each of these traits, the truth is that people vary in each phase of BAC calculations, and involves a number of other factors that cannot be ignored. Alcohol Metabolism Explained: The three stages of alcohol metabolism are absorption, distribution, and elimination. • Absorption is the process by which the body accepts alcohol into the bloodstream. • Distribution is how the alcohol moves throughout the body. • Elimination is the process by which alcohol is broken down or removed from the body. Absorption: Absorption is the process by which alcohol is made available to the fluids of distribution of the body, such as blood, plasma, serum, etc. Typically, about 80 percent of orally-consumed alcohol
  • 3. is absorbed from the small intestines, with the rest absorbed from the stomach. On an empty stomach, more than half of the alcohol consumed will be absorbed within 15 minutes and a maximum blood level will occur in about 20 minutes, with 80 to 90 percent complete absorption occurring within 30 to 60 minutes. Numerous variables affect alcohol absorption and estimation, including the rate of consumption, how much is consumed, the alcohol's concentration, the presence of carbonation in the drinks, food in the stomach, whether the person is taking any medications that can interfere with the gastrointestinal tract, as well as other variables including: • Drinking Pattern • Absorption Time • Food Intake • Individual Variables - Additional Variables Effecting Absorption: • Type of alcohol ingested • Whether alcohol/food ingested was • Illness carbonated or uncarbonated • Medications • Gender • Stimulants (may slow absorption) • Pathological Conditions • Trauma (may slow absorption) • Fatigue/amount of sleep • Race (possibly)
  • 4. Alcohol Elimination (Metabolism): The third process is elimination (metabolism). To ultimately remove alcohol from the body, it must first be inactivated. This is initiated by altering the alcohol's chemical structure into a substance that is more easily excreted by the body, and is often referred to as detoxification. Alcohol is metabolized in the liver by the enzyme dehydrogenase into acetaldehyde, which causes dilation of blood vessels (It’s this dilation that is responsible for hangovers). The acetaldehyde is next metabolized by the enzyme aldehyde dehydrogenase into acetate, which is very similar to vinegar. Measurement of blood serum acetate levels may be an indicator of problem or chronic drinking. Certain drugs can inhibit the aldehyde dehydrogenase enzyme responsible for the second step in metabolizing alcohol, and inhibition of this enzyme causes an increase in blood acetaldehyde levels. One of these drugs is antabuse, which is often used to treat alcoholics. People taking antabuse can become very sick from consuming even a small amount of alcohol. Other such drugs include chloral hydrate and oral anti-diabetic drugs such as Diabinese. Studies show that typically, 80 percent of consumed alcohol enters the blood within five to 10 minutes, 100 percent enters the blood within 30 to 60 minutes, and that alcohol is eliminated from the blood at a rate between .01 and .025 percent per hour. The state crime lab uses .010 to .020 as a ‘standard’ elimination rate (viewed by the State as representing someone with a lower metabolism and benefitting the defendant), though studies demonstrate that individual elimination rates can vary from .008 - .036% per hour. When to Challenge: Pre-trial or Mid-trial? One way to challenge scientific evidence is through a pretrial motion. Under ORS 135.037, you have a right to a pretrial omnibus hearing to determine issues including "[s]uppression of evidence." "Suppression" has been interpreted quite broadly for purposes of another statute (ORS 138.060, governing the State's right to take interlocutory appeals); at least in that context, it's not limited to constitutionally based suppression motions. See State v. Hoare, 20 Or App 439 (1975); State v. Koennecke, 274 Or 169 (1976). In addition to that statutory language, Oregon case law approves the idea of a pretrial hearing on the admissibility of scientific evidence or other evidence with significant prejudicial potential. See State v. O'Key, 321 Or 285, 307 n 29 (1995) ("When proffered scientific evidence raises issues of scientific validity, those issues should be addressed by the trial court in a separate OEC 104(1) hearing, preferably in advance of trial." See also e.g. State v. Stanley, 30 Or App 33, 38 (1977) (“Evidence which carries an unusual potential for prejudice should be ruled upon preliminarily, prior to trial in the case of State's evidence . .")). Alternatively, you can wait until the point in the trial where the State seeks to introduce the evidence, and demand that a proper foundation be laid before that evidence comes in. You should be able to have the jury excluded for this portion - if they're present, they're exposed not only to proffered scientific evidence that may ultimately be deemed inadmissible, but also to the inadmissible portions of the foundational evidence. See OEC 103(3) ("In jury cases, proceedings should be conducted, to the extent practicable, so as to prevent inadmissible evidence from being suggested to the jury by any means . . . ."); OEC 104(3) (hearings on preliminary matters other than the admissibility of confessions should be conducted outside the jury's presence "when the interests of justice require").
  • 5. There are advantages and disadvantages to both options. If you file a pretrial motion, you know going into trial whether you'll have to deal with that evidence or not. Of course, the State knows this too, so depending on the circumstances the preparation factor may be a wash. If you win such a motion, you don't have to worry about the jury hearing about the evidence in the early phases of the trial. Cf. State v. Stanley, supra, 30 Or App at 196 (affirming conviction although evidence referenced early in the trial was ultimately deemed inadmissible: "Where there was no pretrial motion, where both attorneys had mentioned breathalyzer evidence prior to the officer's testimony, and where the reason for the exclusion of the evidence reflects negatively upon the reliability of that evidence, we cannot say as a matter of law that the hearing of foundation evidence before the jury influenced the jury in their fact-finding . . . "). A pretrial motion may more generally alert the prosecution and make them more prepared than they would otherwise be. This is particularly significant where the type of evidence at issue hasn't been approved by any Oregon appellate court, so that the prosecutors must lay the entire Brown/O'Key foundation - no small thing. A prosecutor challenged to do so mid-trial may not be ready with sufficient evidence of scientific validity, error rates, peer-reviewed literature, and all the other factors in the analysis/record to fill the foundational-void. However, if you file a pretrial motion and succeed in getting the evidence excluded, the State has an appeal right that it wouldn't have if the exclusion decision had been made mid-trial. See State v. Hoare, supra, 20 Or App at 444-45 ("When a defendant raises an objection to evidence in advance of trial, he takes the risk that the State may have an opportunity to obtain review of an adverse decision it would otherwise be deprived of if the objection were made during the course of the proceedings."). For this reason, the State may itself ask for a pretrial hearing on the admissibility of its evidence, especially if you've alerted them to the fact that you intend to challenge it. Remember: The proponent of the scientific evidence has the burden of establishing its validity. State v. Perry, 347 Or 110, 122 (2009). This is important in retrograde extrapolation cases, because the mathematical process underlying retrograde extrapolation is based on two assumptions: (1) that at the time of the breath test the defendant was in the eliminative phase of his/her intoxication, when his/her BAC level was decreasing, and (2) that the defendant's blood was eliminating alcohol at a specific rate. To properly determine whether the defendant was in the eliminative phase of intoxication and at what rate the defendant's blood was eliminating alcohol, the criminalist conducting the retrograde extrapolation must take into account several factors applying a range of elimination rates as opposed to a specific value. Without consideration of these factors, retrograde extrapolation should not be considered scientifically- valid. As aptly described by the Alabama Court of Appeals: “[T]he inadequacies of retrograde extrapolation extend beyond mere technical inaccuracies to problems which are inherent in the basic premises and calculations of this technique. These inadequacies render retrograde extrapolation inherently untrustworthy and therefore inappropriate for use as evidence to convict drunk drivers.'") (quoting E. Abbott, "One for the Road" - The Reliability of Retrograde Extrapolation and the Implications for Vermont Statutes, 16 VT.L.Rev. 395, 397 (1991)). Smith v. Tuscaloosa, 601 So. 2d 1136, 1140 (Ala. Crim. App. 1992). To Cross or Not to Cross - That Is the Question: Another decision is how extensive and searching your cross-examination of the proffered expert should be during the admissibility hearing, whether pretrial or mid-trial. Prosecutors sometimes show up apparently thinking of the Brown/O'Key factors as a fairly perfunctory list of yes/no
  • 6. questions. ("Mr.Ms. Expert, has this method been confirmed through studies?" "Yes." "Is there peer-reviewed literature on this method?" "Yes." etc.). If the prosecutor is not well-versed in the law in this area, he or she may simply try to lay only a bare-bones, possibly legally-insufficient foundation. What to do then? One option is to dive into a heavy, thorough cross-examination that exposes the lack of any legitimate basis for the witness's conclusory statements. For example, the State's witnesses may have given testimony on direct regarding error rates, but a good cross might reveal that those rates were not determined by any legitimate, quantitative process. Or the "studies" relied on to validate the State's method might have been done internally, by technicians, without the "studies" having been subjected to peer review or otherwise validated. Cf. State v. Perry, 347 Or 110, (2009) ("[The witness] also described a small, informal CARES study of children with abnormal physical examinations, which found that 90 percent of those children had delayed in disclosing sexual abuse. She acknowledged that the study was not peer reviewed and was not rigorous. We do not consider it as part of the State's portrayal of specialized literature at the OEC 104 hearing."). Remember: at an admissibility hearing, it's not a "sufficiency of the evidence" standard - the evidence only comes in if the court actually decides by a preponderance of the evidence that it's valid. See State v. O'Key, supra, 321 Or at 307 n 29 ("Under OEC 104(1), the trial court is not to decide merely that the proponent has offered enough evidence of validity to enable a reasonable person to conclude that the evidence is valid, but the court is to decide the validity issue."). If you can demonstrate on cross that the witness's conclusory direct testimony was unfounded and should be given little weight, you might move the court’s thinking in your direction in the admissibility analysis. But: it's also possible for that sort of cross to produce testimony that would allow a trial or appellate court to fill the gaps and find the evidence admissible. For that reason, you may decide you're better off with little or no cross, just leaving the record as the State has created it. One thing to note if you're going to try the "minimalist" route: to be safe, you probably need to mention all of the Brown/O'Key factors in your argument before the trial court, or at least all of the ones that might give you some traction on appeal. Otherwise, even though it's the State's burden to lay the foundation for its evidence, you could be deemed to have effectively conceded the unmentioned factors. See State v. Perry, supra, 347 Or at 122 ("In general, we agree with the premise of the State's argument: in multi-factor foundation cases like the present one, for example, the trial court reasonably might assume that some factors are not in dispute if no one mentioned them."). As you can see, there's no universal answer to questions such as whether to make your challenge pretrial or mid-trial and how extensively to cross the State's witnesses. The decisions should be made in light of the various objectives of a Brown/O’Key hearing; these include winning the admissibility argument at the trial court level, developing and preserving a basis for an appeal, and previewing the State's evidence and potentially weakening it at trial (as to this last objective, many of the issues affecting the admissibility analysis will also provide useful cross examination material at trial, and in the admissibility hearing without the jury present you can ask probing questions with comparatively little risk even if you don't know the answers).
  • 7. What To Expect From The State: The State, through the testimony of a crime lab expert, tends to rely heavily upon the Gullberg studies to support the use and admission of retrograde analysis evidence. See Rodney Gullberg, Variation in Blood Alcohol Concentration Following the Last Drink, 10 J. of Police Science & Admin. 289 (1982); Gullberg & McElroy, Comparing Roadside With Subsequent Breath Alcohol Analysis & Their Relevance To the Issue Of Retrograde Extrapolation, 57 Forensic Science International 193 (1992). State Crime Lab Experts: When you're challenging the State's scientific evidence, you'll find yourself in one of two basic situations and dealing with one of two kinds of “expert” witnesses. Though ostensibly-neutral scientists employed by the State to perform various kinds of analysis and testing, in fact each employs various levels of advocacy for the State. Such expert witnesses typically provide evidence establishing the foundation for use of retrograde extrapolation evidence, or more commonly, evidence establishing the application of retrograde extrapolation. If the evidence is of a type that's been previously approved by an Oregon appellate court (for example, HGN evidence in a DUII case), the admissibility requirements are relatively limited; the State basically has to show that the witness is qualified to apply the method or technique and did so correctly in your case. See, e.g., State v. O'Key, 321 Or 285, 293 n 8 (1995). However, absent such appellate approval, the State needs to lay a much more comprehensive foundation. The distinction between the expert witnesses role (and qualification) for establishing foundation vs. application is an important one to keep in mind whenever the State has to lay a full Brown/O'Key foundation. Pay close attention to the qualifications of the witness the State puts forward at the admissibility hearing, as you may find out that the State’s ‘foundation expert’ is only qualified to testify to the application, not the underlying science. Is that witness a true "foundation-level" expert? Is s/he qualified to explain the scientific principles underlying the test, how it works, what the potential sources of error are, etc.? (Note: "qualified" means more than being able to read those things out of a book or manual and regurgitate them to the court.). Or is the State’s expert someone who knows how to do the test (like the police officer in State v. Rood, 83 Or App 451 (1987))? Remember, the key focus is not whether the witness gives foundational evidence (much as a police officer or lab tech is capable of doing) but whether the witness is qualified to testify to the scientific principles supporting the use of retrograde extrapolation. - A Random Sampling of State “Experts”: L L Please Note: All ‘rankings’ are purely subjective and are based on the author’s personal experience together with a non-scientific telephone/email poll of a number of experienced Oregon criminal defense lawyers.
  • 8. Robert Jones: ‘Ranked’ [by defense counsel] as mostly neutral, with mild-to-moderate moments of advocacy for the State. Acknowledges non-supportive information/studies in his testimony, and is typically willing to acknowledge shortcomings in analysis/science. Paul Refalo: ‘Ranked’ [by defense counsel] as the most adversarial and strongest advocate for the State’s position in a given case. Tends to omit non-supportive information/studies in his testimony, exposing himself to multiple impeachment and/or ‘why didn’t the State tell us this’ opportunities. Jennifer Bray: ‘Ranked’ [by defense counsel] as mostly neutral, with mild-to-moderate moments of advocacy for the State. Acknowledges non-supportive information/studies in her testimony, is often able to respond by offering contra studies and crime lab procedural/confirmation testing, typically willing to acknowledge shortcomings in analysis/science. Case Example Q. "What do you know about rates of absorption?” A. "Well rates of absorption that’s not something we study with our blood-breath correlation studies, I can tell you what is in the literature it’s just that it’s very highly variable from individual to individual and even with the same individual from day to day you can have different absorption rates * * * there are so many factors that can be involved with that. What kind of drink it was, was it carbonated or not, is there any food in the stomach, is that person * * * under a lot of stress are they relaxed different things can affect how fast that alcohol is absorbed.” Testimony of Robert Jones State v.Vaughn - Clackamas Co Case CR08-10989 [September 7, 2008] Case Example See transcript from State v. Rubic, Clackamas Co. Case CR10-14169 [June 14, 2011]. Simply loaded with nonsense and evasion, leading to the court finding Mr. Refalo ‘not credible.’ Case Example Q. "And this retrograde extrapolation model, has this been accepted in the scientific community." A. "There's been a lot of controversy on it, and it's because studies are performed differently and there's problems with it." * * * * * Q. “There’s a plateau at some point, isn’t there.” A. “Well, *** there is. It’s the peak, the highest point or blood alcohol concentration reached, and that’s when absorption and elimination equal each other.” Testimony of Jennifer Bray State v. Wendt - Linn Co Case 09-122393 [February 18, 2011]
  • 9. Ú Moral Of The Story Ú When preparing to cross-examine State experts, get transcripts! L L Discovery - Crime Lab Testing & Reporting: In cases involving evidence derived through retrograde extrapolation, it’s absolutely necessary to obtain and analyze the test reports and all related notes from the crime lab. Case Example Q. “And if somebody is pre-peak, any kind of estimate that you would give would be erroneous? A. Yeah. I would have to possibly back out the drinks that were within a half an hour of the time in question. Q. So if you didn't know what time somebody stopped drinking, would that have any effect on your ability to do a retrograde extrapolation? A. Yes. We like to have them stop drinking within a half an hour of the time in question. If they don't stop drinking within that time, but we do know how much they had to drink then we just subtract that from the value of the estimate.” * * * * * Q. So if you have a known blood alcohol level, you can work backwards based on that elimination rate? A. Well, to be able to do this estimation I would have to assume that the person was post-peak, meaning that they've already reached their maximum blood alcohol level prior to the time in question. * * * * * Q. And if the person is pre-peak -- that means they have not metabolized all their alcohol -- then there's no way to even calculate it; is that correct? A. Yeah. We'd have to subtract out any drinks within a period of time, right before the time in question. And so it would be a very, I guess, kind of raw estimate. Testimony of Jennifer Bray State v. Montgomery - Lake Co Case 08022CR93 [September 25, 2009] Special Note to OCDLA Members - many Pond-Dwellers have/share copies of transcripts from past trials upon request.
  • 10. Rounding Errors: When extrapolating a BAC from two (or more) samples to a prior point in time, the state crime lab is required to adhere to analytical, computational and reporting standards specified by administrative rule. Specifically, the lower limit of quantitation for this method is administratively defined as 0.0100% (w/v). Source: Oregon State Police Forensic Services Division Blood Alcohol Procedures Manual §10.0 - Reporting - Item 2: “Other Reporting Considerations.” Single-Point Analysis: Trending A basic premise for application of retrograde extrapolation is that, at the time of the breath test the defendant was in the eliminative phase of his intoxication, when his/her BAC level was decreasing. If a person is tested while in the absorption phase their BAC at the time of the test will be higher than their BAC while driving. If tested while in the elimination phase their BAC at the time of the test could be lower than while driving, depending on whether they had reached their peak before or after the stop. Obviously, the greater the length of time between the driving and the test, the greater the potential variation between the two BACs. - Going Up or Down? - Case Example - Crime Lab Worksheet Reveals Sample One Taken @ 03:51 Sample Two Taken @ 04:21 Reported Test Values: 0.059 Reported Test Values: 0.052 Actual Test Values: 0.0585, 0.0589 Actual Test Values: 0.0527, 0.0522 +/-.0004 (rounds up to next higher value) +/-.0005 (rounds down) The criminalist may attempt to use the difference between .059 and .052 (.007) as a "dissipation" rate for ½ hr, and then "extrapolate" this to .014/hr as a dissipation rate (.007 x 2). Problem: The internal error rate is +/-.002%, which means .059 could be .057 and .052 could be .054, creating a potential difference of .003%. Based on this difference, one could then assume that the "dissipation rate" is .006 (.003 x 2). Cross-X: Administrative rule provides that the lower limit of quantitation is .0100%. This means that any measured at values less than .010 (i.e. .010*%) becomes unreliable. If the third digit is "reliable" (i.e. .058* and .052*) why doesn't the lab report values less than .01? [Answer: because a value less than .010 is defined by administrative rule as ‘unreliable.’]. Source: OSP Forensic Services Division “Blood Alcohol Procedures Manual” p. 27 (Rev. 6/7/2010).
  • 11. L L L L Plateau: Once in the blood, alcohol is carried throughout the body. The alcohol diffuses into tissues and fluids according to their water content. During the absorption phase, the BAC of arterial blood is greater than the BAC of venous blood. Arteries carry blood to a tissue, and veins remove blood from the tissue. At equilibrium, where the tissue has absorbed a proportionate quantity of alcohol, the BAC of arterial blood is equal to the BAC of venous blood. When this occurs the rate of absorption is equal to the rate of elimination and hence the blood alcohol concentration does not change. In some cases, a subject may develop a plateau, where the blood alcohol level does not change for up to two hours. After two hours, the rate of elimination will exceed the rate of absorption and the blood alcohol level will begin to decrease. Filling in the “Variable Vacuum” on Cross Examination: When challenging the State’s criminalist on his/her back-extrapolation calculations, often the greatest opportunities come from identifying and pointing out which variables the criminologist did not consider or considered using erroneous data [e.g. weight on ODL vs. actual weight, etc.], and then having the defendant testify to fill in or correct the variable information during a suppression hearing. Be sure to pin the criminologist down on what information was known to/considered by the criminologist at the time s/he made her/his retrograde extrapolation calculations, secure in the knowledge that the ‘new’ information disclosed by the defendant during the suppression hearing cannot be used to support the criminologists’s opinion at trial (but may be used for impeachment purposes). See ORS 135.037(4). Note: the Intoxilyzer takes two readings from two separate breath samples provided only about two minutes apart. For the purposes of drawing an alcohol concentration curve (ACC) these two samples constitute only a single reading. An accurate ACC would require many more points of data than the Intoxilyzer provides. Consequently, the "single" reading provided by the machine does not provide enough information to determine whether a person is in the absorption phase or the elimination phase at the time of the breath test. ORS 135.037(4): At the conclusion of the hearing and prior to trial the court shall prepare and file an order setting forth all rulings of the court on issues raised under subsection (2) of this section. The court shall further prepare and file a memorandum of other matters agreed upon at the hearing. Except in a prosecution of the defendant for perjury or false swearing, or impeachment of the defendant, admissions made by the defendant or the attorney of the defendant at the hearing may not be used against the defendant unless the admissions are reduced to writing and signed by the defendant and the attorney.
  • 12. 7 Reasons to NOT Use Retrograde Extrapolation: 1. Not all blood and breath alcohol curves follow the Widmark patterns nor is the elimination necessarily linear. 2. Alcohol absorption is not always complete within 60 to 90 minutes, as often claimed. 3. The peak alcohol concentration cannot be validly predicted or established in an individual instance without frequent and timely measurements of alcohol concentrations. 4. It is not possible to establish whether an individual is in the absorption or elimination phase, or to establish the mean overall rate of alcohol elimination from the blood or breath, from the results of two consecutive blood or breath alcohol measurements, however timed. 5. Significantly large short-term fluctuations occur in some subjects and result in marked positive and negative departures from the alcohol concentration trend line. 6. Short-term, marked oscillation of the blood or breath alcohol concentration can occur at various points of the curve, resulting in repeated excursions of the alcohol concentration above and below a given concentration (such as 80 or 100 mg/dl) within a few minutes or for hours. 7. No forensically-valid forward or backward extrapolation of blood or breath alcohol concentrations is ordinarily possible for a given subject and occasion solely on the basis of time and individual analysis results. Making Use of Studies, Articles & Publications: “Retrograde extrapolation applied to the data employing an assumed 0.15g/210 l/h yielded a small but significant overestimate of the actual known BAC from breath testing. Evidentiary analysis performed within two hours of driving will provide good estimates, and certainly not overestimates, of the BAC existing at the time of driving and it appears that extrapolation may be unwarranted in these cases.” Comparing Roadside With Subsequent Breath Alcohol Analysis And Their Relevance To the Issue Of Retrograde Extrapolation, Forensic Science International, 57 (1992) 193 - 201. ~ ~ ~ ~ ~ “Back extrapolation determinations of blood alcohol levels based on a single rate of decrease in concentration vs. a non-linear rate of decrease in concentration (particularly if low) must often yield estimates bordering on wild guesses.” The Metabolism and Pharmocokinetics of Alcohol in Man, J. Forens. Sci Soc (1977), 17, 49. ~ ~ ~ ~ ~
  • 13. “The simple Widmark calculation used by many experts results in a higher BAC than any of the other methods, whereas the other methods tend to agree with each other and not with Widmark. The primary reason for the elevated numbers obtained when using the Widmark ‘r’ value is that the other methods calculate ‘r’ based on measured parameters rather than relying on the average value obtained from a small group of individuals in 1932. “ The Estimation of Blood Alcohol Concentration Widmark Revisited, Forensic Sci. Med. Pathol.: 3:1:33 ~ ~ ~ ~ ~ “A trend-line curve is markedly inappropriate or useless for attempts to engage in retrograde extrapolation, for, among others, three main reasons: (1) lack of knowledge about the timing of the alcohol consumption peak; (2) ignorance about the mathematical characteristics (e.g. linear, pseudo-linear, exponential); and the mean rate of change in the individual’s blood or breath alcohol elimination curve; and (3) unpredictable irregularities in the curve, especially short-term fluctuations from the best-fit trend line of the blood or breach alcohol curve.” “Most alcohol pharmacokinetics parameters are subject to a wide inter-subject variability, as exemplified by peak alcohol concentrations reached on ingestion of identical weight-adjusted doses, time to peak after end of drinking and rate of alcohol elimination from the blood. This great biological inter-subject variability, when combines with sex-, age and time-related differences, makes the blood alcohol on information in widely distributed alcohol consumption nomgrams and tables based on mean data inappropriate as a guide for the drinking behaviors of individuals.” “Breath and blood alcohol time curves are subject to short-term fluctuations from the trend line and other irregularities, and often do not follow the typical Widmark pattern.” Absorption, Distribution and Elimination of Alcohol: Highway Safety Aspects. Kurt Dubowski, PhD, Journal of Studies on Alcohol, Supplement No. 10, July 1985 pp 103, 105 & 106. ~ ~ ~ ~ ~ “..... the practice of making a back estimation of a person’s BAC is inevitably a controversial issue.” Karch - Drug Abuse Handbook, Chap. 13.2 by A.W. Jones & B. Logan ~ ~ ~ ~ ~ “Uncertainties surrounding the absorption kinetics of alcohol make it difficult for a forensic expert witness to state unequivocally whether the BAC was rising or falling at the time of the road-traffic accident.” Alcohol, Drugs & Driving 1992 - Physiological Aspects of Breath-Alcohol Measurements by A.W. Jones
  • 14. “No forensically-valid forward or backward extrapolation of blood or breath alcohol concentrations is ordinarily possible in a given subject and occasion solely on the basis of time and individual analysis results.” Absorption, Distribution and Elimination of Alcohol: Highway Safety Aspects. Kurt Dubowski, PhD, Journal of Studies on Alcohol, Supplement No. 10, July 1985 pp 103, 106. ~ ~ ~ ~ ~ Retrograde extrapolation is performed when a blood or a breath alcohol concentration is used in conjunction with a drinking history to estimate an alcohol concentration at some time before the subject provided the specimen. Often this time is the time of observed driving, the officer’s stop or the time of the crash. This estimation cannot be simply done by adding back for the expected elimination using an average rate. Lecture at the Borkenstein Alcohol Course: Pharmacology of Alcohol-Extrapolations. Dr. Robert Forney Oregon Cases Addressing Retrograde Extrapolation: State v. Eumana-Moranchel, 352 Or 1 (2012) (Retrograde extrapolation analysis is based on and derived from a chemical test [breath/blood/urine] and that * * * the retrograde extrapolation analysis, applied to the chemical test result, explains that the chemical test “shows” that defendant drove with a BAC of .08 percent or more per ORS 813.010(1)). http://www.publications.ojd.state.or.us/docs/S059602.pdf State v. Whitmore, 257 Or App 664 (2013) When the State offers an expert on blood alcohol dissipation and retrograde extrapolation, it must first make a foundational showing that the expert’s methods were scientifically valid pursuant to Brown/O’Key. Here, the expert had a background in forensic science and her knowledge of blood alcohol chemistry was based on the literature in the field. Because she was offering a scientific opinion, the foundational showing needed to be made. http://www.publications.ojd.state.or.us/docs/A146430.pdf State v. Montgomery, 256 Or App 222 (2013) (Court erred in denying motion to exclude DRE Officer’s testimony relating to rate of dissipation of alcohol, finding that the State failed to lay a scientific foundation for evidence involving the precise rate of dissipation of alcohol (with a lesson to defense counsel)). http://www.publications.ojd.state.or.us/docs/A144361.pdf State v. Ohotto Or App (February 12, 2014) (the court erred when admitting the testimony of a deputy estimating the ‘likely’ number of drinks required for defendant to reach a .17 BAC,’ because the State failed to establish a sufficient foundation for expertise in the field through an assessment of the deputy's particular qualifications. http://www.publications.ojd.state.or.us/docs/A148725.pdf Other Jurisdictions Addressing Retrograde Extrapolation: A list of case citations to other jurisdictions is included in the Supplemental Materials.
  • 15. Judicial Words of Wisdom: “ * * * if retrograde extrapolation standing alone is sufficient to establish a violation of the statute, the statute risks over inclusivity, because there is no limit to how far the State may extrapolate to secure a conviction. The majority's interpretation would permit the State to prove through retrograde extrapolation not only that a person with a .07 percent BAC was over .08 percent one hour earlier, but also that a person with a .01 percent BAC was over .08 percent eight hours earlier. The scientific principles supporting retrograde extrapolation have not advanced to such a state today—and certainly had not in 1975 when the legislature first enacted this statute—to permit such a conviction beyond a reasonable doubt. The plain meaning of the text of the statute also supports my conclusion that the legislature had no intention of including retrograde extrapolation as a “chemical analysis” under paragraph (a). The legislature required that a BAC of .08 percent or more must be “shown by chemical analysis of the breath or blood of the person” in order to support a determination that a person has committed the offense of driving under the influence under ORS 813.010(1)(a). The legislature did not provide that a BAC of less than .08 percent, as shown by chemical analysis, could somehow be rehabilitated or explained away by expert testimony or any other circumstantial evidence under paragraph (a). The terms the legislature used in paragraph (a) plainly require that a chemical analysis made under ORS 813.100, ORS 813.140, or ORS 813.150 must itself show that a person has a BAC of .08 or greater. That reading of the text is well supported by the applicable definitions of the terms the legislature used in the statute and by the general rules of grammatical construction that inform our understanding of statutory terms.” De Muniz, J, joined by Durham and Walters, dissenting opinion in State v. Eumana-Moranchel, 352 Or 1, 15 - 16, 277 P3d 549 (2012) (a definate “Must-Read”). Words of Advice - 1. Do your homework - be the most informed person in the courtroom on your issue(s) 2. Consult with an expert - listen to/learn from your expert 3. Use an expert witness at trial to explain and provide an evidentiary foundation for your challenges. Prepare to co-op the State’s expert(s) 4. Evaluate and consider the preparation and competency of your prosecutor in your pre-trial/trial strategy planning/decisions 5. Educate your trial judge 6. Get transcripts of prior testimony for State experts Read/consider the issues addressed by the National Research Council of the National Academies in Strengthening Forensic Science in the United States: A Path Forward. Washington, DC: The National Academies Press, (2009) http://www.nap.edu/openbook.php?record_id=12589.
  • 16. Additional Challenges(?): ORS 813.010 - Retrograde Extrapolation is not a “chemical analysis” (1) A person commits the offense of driving while under the influence of intoxicants if the person drives a vehicle while the person: (a) Has 0.08 percent or more by weight of alcohol in the blood of the person as shown by chemical analysis of the breath or blood of the person made under ORS 813.100 (implied consent to breath or blood test), 813.140 (chemical test with consent) or 813.150 (chemical test at request of arrested person); (b) Is under the influence of intoxicating liquor, a controlled substance or an inhalant; or, (c) Is under the influence of any combination of intoxicating liquor, an inhalant and a controlled substance. Challenge Opportunity? - In order to submit evidence of a defendant’s blood-alcohol content, the State must “show by chemical analysis” that the defendant’s blood-alcohol content was .08 or higher. Perhaps not. See State v. Eumana-Moranchel, 352 Or 1, 9, 277 P3d 549 (2012): Read Justice De Muniz’ dissent for a lengthy discussion and potential challenge opportunities to retrograde extrapolation of a defendant’s blood-alcohol content. Acknowledgments Special thanks are given to OCDLA Member Kenn Meneely of Willamette Valley Forensics, LLC for portions of his trial materials used in this presentation, as well as his knowledge (& patience) assisting and educating numerous defense counsel on retrograde extrapolation. Thanks also go out to OCDLA member Russell Barnett (“RB3") for his inspired tennis-ball metaphor (and cross-examination) from State v. Zamede, Clackamas Co. Circuit Court Case CR1113196 (May 17, 2012). Thanks also go out to OCDLA member Kevin Sali for his contributions to and materials used from OCDLA’s Library of Defense. Thanks also to David R. for his confidence and investment supporting this author’s education and application of the science of retrograde extrapolation, as well as for his extraordinary commitment to the pursuit of Science and Justice. Finally, immeasurable thanks go out to the many OCDLA members who regularly swim the Pond and contribute their experience, wisdom and support for the cause of defending others.
  • 17. * * * Supplemental Materials Follow * * *
  • 21. Other Jurisdictions Addressing Retrograde Extrapolation
  • 25. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Dubowski, Absorption, Distribution and Elimination of Alcohol: Highway Safety Aspects Journal1 of Studies of Alcohol (1985); Mason and Dubowski, Breath Alcohol Analysis: Uses, Methods, and Some Forensic Problems – Review and Opinion, 21 Journal of Forensic Sciences 9 (1976); Simpson, Medicolegal Alcohol Determination: Implications and Consequences of Irregularities in Blood Alcohol Page 1 – MOTION IN LIMINE TO EXCLUDE EVIDENCE OF RETROGRADE EXTRAPOLATION WITHOUT PROPER FOUNDATION LAW OFFICES OF BRIAN COX 142 West 8 Avenueth Eugene, Oregon 97401 Telephone: (541) 683-7151 † Facsimile: (541) 485-7742 coxandassociates@coxassociates.info IN THE CIRCUIT COURT OF THE STATE OF OREGON FOR THE COUNTY OF NAUGHT STATE OF OREGON, ) Case No. XX-XXXXX ) Plaintiff, ) MOTION IN LIMINE TO EXCLUDE ) EVIDENCE OF RETROGRADE v. ) EXTRAPOLATION WITHOUT ) PROPER FOUNDATION MISS MISTY ACCUSED, ) ) ORAL ARGUMENT REQUESTED Defendant. ) Motion This motion seeks to require the State to provide an adequate Brown / O’Key / Daubert / Kuhmo foundation prior to the admissibility of any evidence relating to retrograde extrapolation, or in the absence of adequate foundation, to object to admission of any such information and/or evidence relating to retrograde extrapolation pursuant to OEC 401, 702 & 403. Statement of Facts Miss Accused was involved in a collision between two motor vehicles on January 1 ,st 2014. Blood and urine samples were taken at the hospital after the accident. It is expected that the State will attempt to question an un-designated Expert Witness (Criminalist) in a manner designed to extract testimony relating to Miss Accused’s projected/average blood-alcohol level at the time of driving derived from information obtained from these samples. This proffered analytical approach is known as “retrograde extrapolation” and is not considered to be reliable or generally accepted by a consensus of scientists competent in forensic alcohol analysis. It is1
  • 26. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Concentrations vs Time Curves, 16 Journal of Analytical Toxicology (1992). Winek and Murphy, The Rate and Kinetic Order of Ethanol Elimination, 29 Forensic Science2 International 159 (1984); Jones, Disappearance Rate of Ethanol From the Blood of Human Subjects: Implications in Forensic Toxicology, 38 Journal of Forensics 103 (1993). 3 Nat'l Inst. on Alcohol Abuse & Alcoholism, Alcohol Alert, "Alcohol Metabolism," No. 35 (Jan. 1997). Jennifer Pariser, Note: In Vino Veritas: The Truth About Blood Alcohol Presumptions in State4 Drunk Driving Law, 64 N.Y.U.L. Rev. 141, 146 (1989), citing S. Brent & S. Stiller, Handling Drunk Driving Cases, § 4:2 (1985); Edward Fitzgerald & Dr. David Hume, The Single Chemical Test for Intoxication: A Challenge to Admissibility, 66 Mass. L. Rev. 23, 28 (1981). Pariser, 64 N.Y.U.L. Rev. at 147, citing 2 R. Erwin, Defense of Drunk Driving Cases Criminal /5 Civil §15.04[1][b][i], at 15 (3d ed. 1988); Rodney Gullberg, Variation in Blood Alcohol Concentration Following the Last Drink, 10 J. of Police Science & Admin. 289 (1982); Alan Jones et al., Peak Blood- Ethanol Concentration and the Time of Its Occurrence After Rapid Drinking on an Empty Stomach, 36 J. of Forensic Science 376, 381 (1991). 6 NIAAA Alcohol Alert, "Alcohol Metabolism," No. 35 (Jan. 1997). 7 Y. Al-Lanqawi et al., Ethanol Kinetics: Extent of Error in Back Extrapolation Procedures, 34 British J. of Clinical Pharmacology 316, 320 (1992). Page 2 – MOTION IN LIMINE TO EXCLUDE EVIDENCE OF RETROGRADE EXTRAPOLATION WITHOUT PROPER FOUNDATION LAW OFFICES OF BRIAN COX 142 West 8 Avenueth Eugene, Oregon 97401 Telephone: (541) 683-7151 † Facsimile: (541) 485-7742 coxandassociates@coxassociates.info further expected that the Criminalist will base his/her testimony on “averages” that do not take into consideration the scientific fact that absorption and elimination rates are highly variable and are effected by a myriad of factors, most commonly including weight, gender, physical condition, metabolic rate, time of day, when, what, and how much was last eaten, when, what, and how much and how the subject drank, whether any medications were taken or not taken, emotional state, and whether the subject is an alcoholic.2 Retrograde extrapolation is the computation back in time of the blood-alcohol level - that is, the estimation of the level at the time of driving based on a test result from some later time. As alcohol is consumed, it passes from the stomach and intestines into the blood, a process referred to as absorption. When the alcohol reaches the brain and nervous system, the3 characteristic signs of intoxication begin to show. The length of time necessary for the alcohol4 to be absorbed depends on a variety of factors, including the presence and type of food in the stomach, the person's gender, the person's weight, the person's age, the person's mental state,5 6 7 8 9
  • 27. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Ibid.8 Jones et al., 36 J. of Forensic Science at 381.9 Ibid.10 11 Ibid. Gullberg, 10 J. of Police Science & Admin. at 289.12 13 Ibid. 14 All of Widmark's work was done on subjects who drank a metered amount of alcohol on an empty stomach. Id. at 3-2 et seq. In the original test group of 30 subjects, only 3 (10%) tested in the absorption range of 0.65 and 0.70, 19 (63%) tested under 0.65 and 8 (27%) tested over 0.65. The subjects' elimination rates varied from 0.006 to 0.04 with most being widely distributed between 0.010 and 0.020. Pariser, 64 N.Y.U.L. Rev. at 152, citing W. Frajola, Defending Drinking Drivers 16.1 (1985).15 Page 3 – MOTION IN LIMINE TO EXCLUDE EVIDENCE OF RETROGRADE EXTRAPOLATION WITHOUT PROPER FOUNDATION LAW OFFICES OF BRIAN COX 142 West 8 Avenueth Eugene, Oregon 97401 Telephone: (541) 683-7151 † Facsimile: (541) 485-7742 coxandassociates@coxassociates.info the drinking pattern, the type of beverage consumed, the amount consumed, and the time10 11 12 period of alcohol consumption. At some point after drinking has ceased, the person's BAC will13 reach a peak. After the peak, the BAC will begin to fall as alcohol is eliminated from the person's body. The body eliminates alcohol through the liver at a slow but consistent rate. In 1932, Swedish chemist E.M.P. Widmark first calculated absorption and elimination14 rates in the body, and his work still represents the benchmark for other scientists' studies today. Widmark created what we know today as the "BAC curve," which represents the rise and fall of an individual's BAC as his body absorbs and eliminates alcohol. A reading from a single breath test will not reflect where the person is on his BAC curve. In other words, it will not indicate whether the person is in the absorption phase, at his peak, or in the elimination phase.15 If a driver is tested while in the absorption phase, his BAC at the time of the test will be higher than his BAC while driving. If tested while in the elimination phase, his BAC at the time of the test could be lower than while driving, depending on whether he had reached his peak before or after he was stopped. The greater the length of time between the driving and the test, /////
  • 28. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 See, Dubwoski, fn. 1, supra.16 297 Or 404, 687 P2d 751 (1984).17 State v. Brown, 297 Or at 417.18 State v. O’Key, 321 Or 285, 302 - 303, 899 P2d 663 (1995).19 Page 4 – MOTION IN LIMINE TO EXCLUDE EVIDENCE OF RETROGRADE EXTRAPOLATION WITHOUT PROPER FOUNDATION LAW OFFICES OF BRIAN COX 142 West 8 Avenueth Eugene, Oregon 97401 Telephone: (541) 683-7151 † Facsimile: (541) 485-7742 coxandassociates@coxassociates.info the greater the potential variation between the two BAC levels.16 Even if retrograde extrapolation were scientifically valid, the state is unable to provide a sufficient factual foundation for it to be useful in this case. There is insufficient knowledge as to the time and quantity of drinking as well as other physiological factors which would have to be accounted for, in order to even begin to apply any retrograde extrapolation. 1. The Retrograde Extrapolation Used in this Case must Be Judged under the Brown / O’Key Standard of Admissibility In 1984 the Oregon Supreme Court reached a decision in State v. Brown regarding general17 principlesofadmissibilityofexperttestimonybasedonnewscientifictechniques.InStatev. Brown, the court required seven factors to consider when deciding the admissibility of evidence based on scientific techniques; those being: (1) The technique’s general acceptance in the filed; (2) The expert’s qualifications and stature; (3) The use which has been made of the technique; (4) The potential rate of error; (5) The existence of specialized literature; (6) The novelty of the invention; and, (7) The extent to which the technique relies on the subjective interpretation of the expert.18 The court further illuminated this issue in State v. O’Key as follows:19 Thus, under the Daubert approach, a trial court, faced with a proffer of expert scientific testimony, must determine at the outset, pursuant to FRE 104(a), whether
  • 29. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Daubert v. Merrill Dow Pharmaceuticals, Inc. 509 U.S. 579 (1993); See also Kumho Tire Co.,20 Ltd. v. Carmichael (1999) U.S., 119 S. Ct. 1167. Kumho Tire at 1175 (emphasis added).21 Ibid, at 1176.22 Page 5 – MOTION IN LIMINE TO EXCLUDE EVIDENCE OF RETROGRADE EXTRAPOLATION WITHOUT PROPER FOUNDATION LAW OFFICES OF BRIAN COX 142 West 8 Avenueth Eugene, Oregon 97401 Telephone: (541) 683-7151 † Facsimile: (541) 485-7742 coxandassociates@coxassociates.info the proposed evidence is based on scientifically valid principles and is pertinent to the issue to which it is directed. 509 U.S. at ---- n. 10, 113 S. Ct. at 2796 n. 10, 125 L. Ed.2d at 482 n. 10. The proponent of the evidence has the burden of establishing those matters by a preponderance of the evidence. Id. A. Use of expert testimony guided by Oregon Evidence Code §§ 702 & 703. Admissibility of scientific evidence is determined by the court pretrial. Such an evaluation of the admissibility of the opinion has been described as the “gate keeping” function of the trial court. This entails a preliminary assessment of whether the reasoning or methodology underlying the testimony is scientifically valid and of whether that reasoning or methodology properly can be applied to the facts at issue.20 In Kumho, supra, the United States Supreme Court analyzed addressed the analysis of the “gate keeping” role Federal Rules of Evidence as determined by Daubert, supra, its analysis of the “gate keeping” role under any standard, including the standard required under Brown and O’Key equally applies. The Court referred to this position by stating that “the gate keeping inquiry” of Daubert, supra, is applicable when “the relevant reliability concerns may focus upon personal knowledge or experience” of the witness. This is true because “some of Daubert’s questions can21 help to evaluate the reliability even of experience-based testimony.”22 2. The Retrograde Extrapolation Used in this Case Do Not Pass Brown In State v. O’Key, the Supreme Court adopted the Daubert model and also held that the burden of showing general acceptance lies with the proponent of the evidence to show a “scientific consensus.”TheCourtnotedthat “ifafairreviewoftheliteraturedisclosesthatscientistssignificant in either number or expertise publicly oppose the technique as unreliable, then the court may safely
  • 30. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 State v. O’Key, at 55 - 56.23 Ring v. Taylor, 141 Ariz. 56, 69, 685 P.2d 121, 134 n.6 (Ariz. Ct. App. 1984)(Comment made in a24 footnote without citation to further authority). Page 6 – MOTION IN LIMINE TO EXCLUDE EVIDENCE OF RETROGRADE EXTRAPOLATION WITHOUT PROPER FOUNDATION LAW OFFICES OF BRIAN COX 142 West 8 Avenueth Eugene, Oregon 97401 Telephone: (541) 683-7151 † Facsimile: (541) 485-7742 coxandassociates@coxassociates.info conclude there is no such consensus at the present time.”23 In Mata v State of Texas, 46 SW 3d 902 (Tex. Crim. App. 2001), the Court of Criminal Appeals overturned a conviction of a drunk driving defendant who had a 0.19% blood alcohol level measured by a breath test because of the improper introduction of unreliable evidence of retrograde extrapolation. The opinion of the Court carefully analyzed the state of current scientific literature in the area of retrograde extrapolation and detailed the opinions of a number of leading experts in the field. In addition, the Court analyzed case law from other states in the area and concluded that Arizona is the sole state finding that retrograde extrapolation has “achieved general acceptance in the scientific field.” The State of Alabama disagreed in Smith v. Tuscaloosa,601 So.2d 1136, 114024 (Ala. Crim. App. 1992) quoting E. Abbott, "One for the Road" - The Reliability of Retrograde Extrapolation and the Implications for Vermont Statutes, 16 Vt.L.Rev. 395, 397 (1991): “[C]areful analysis of these studies indicates that retrograde extrapolation is an unreliable method of determining a defendant's condition at the time of operation. The inadequacies of retrograde extrapolation extend beyond mere technical inaccuracies to problems which are inherent in the basic premises and calculations of this technique. These inadequacies render retrograde extrapolation inherently untrustworthy and therefore inappropriate for use as evidence to convict drunk drivers.” It is therefore clear from the analysis adopted byvirtually all states that retrograde extrapolation has not received the state of general acceptance in the relevant scientific community of forensic toxicology in general. Furthermore, it is universally accepted that any attempt at extrapolation without the necessary foundational information to limit the variations of the Widmark formula is “junk science.” In the Concurring Opinion in Mata v. State of Texas, Justice Johnson highlighted the difficulty in accurately trying to predict a blood alcohol level at a time earlier than measurement and pointed out:
  • 31. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Page 7 – MOTION IN LIMINE TO EXCLUDE EVIDENCE OF RETROGRADE EXTRAPOLATION WITHOUT PROPER FOUNDATION LAW OFFICES OF BRIAN COX 142 West 8 Avenueth Eugene, Oregon 97401 Telephone: (541) 683-7151 † Facsimile: (541) 485-7742 coxandassociates@coxassociates.info “A simple mathematical formula for the number of possible combinations of variables is 2 to the power equal to the number of variables, e.g., 5 variables indicates 25, producing 32 possible results. Noted above are at least twenty variables. The number of possible results is thus 220, or 1,048,576. However, this simple equation assumes that each variable has only two values and does not consider any possible interactions between variables. The general equation is the number of possible values, "m," raised to the power of the number of variables, "n," or mn. Assuming an average of 5 values per variable and twenty variables, the number of possibleresults, 520, is 24,414,062. Each variable in the BAC calculation has many possible values. Many of the variables have a possibility of interacting with each other and further complicating the matter. Even assuming a relatively small number of possible values, the number of possible results increases exponentially and quickly becomes mind-boggling. Conclusion The standard for admissibility of evidence based on new scientific techniques first propounded in Brown, and left unchanged by Daubert, is applicable to retrograde extrapolation. Pursuant to the California Evidence Code and the recent decision of the United States Supreme Court in Kumho, the Brown standard is applicable to testimony based on training and experience as well as more traditional “scientific” knowledge. Under that standard, evidence of retrograde extrapolation is inadmissible until shown to be in conformance with Brown, supra., which is difficult and particularly-unlikelyunder the facts of this case. The retrograde extrapolation tests and calculations used in this case do not and cannot be shown to meet this standards for reliability required in order to provide adequate evidentiary foundation for admission of such information at trial, and therefore it should and must be excluded. Dated this 7 day of March, 2014.th COX & ASSOCIATES, LLC By: Brian D. Cox, OSB 902405 Of Attorneys for Miss Accused
  • 32. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Page 8 – MOTION IN LIMINE TO EXCLUDE EVIDENCE OF RETROGRADE EXTRAPOLATION WITHOUT PROPER FOUNDATION LAW OFFICES OF BRIAN COX 142 West 8 Avenueth Eugene, Oregon 97401 Telephone: (541) 683-7151 † Facsimile: (541) 485-7742 coxandassociates@coxassociates.info Summary of Exhibits [Full Articles/Studies to Be Offered During Hearing] Relating to Timed Effect of Marijuana Consumption Exhibit 1: Redwood Toxicology Laboratory Reference Guide Summary: Once in the blood, THC is bound to blood proteins and carried throughout the body where it is either absorbed into body tissues or transformed by the liver into the water soluble metabolites 11-hyroxy-THC and carboxy-THC. These water soluble metabolites are readily excreted into the urine, with the inactive metabolite carboxy-THC being the predominant metabolite detected. Initially, TCH is quickly absorbed into the blood stream where it is carried to the liver and metabolized. Because THC tends to be stored in fatty tissues, it accumulates faster than it can be eliminated in chronic repetitive smokers. This leads to extended retention of THC which is then eliminated from the body at a relatively constant rate with an average elimination half-life being estimated at 18-30 hours. Urinary concentrations of THC are very difficult to interpret due to variables such as dosage of the THC ingested, frequency of use, timing of urine collection relative to last exposure to marijuana, rate of release of stored cannabinoids in adipose tissue, and an individual’s hydration rate. Therefore, the detection of THC metabolites in urine is only an indication of past marijuana use and is not related to the degree of intoxication or impairment. [Marijuana (TCH) Drug Information, p. 43]. Exhibit 2: Drug Evaluation And Classification Training Program - The Drug Recognition Expert School. US Department of Transportation, Transportation Safety Institute National Highway Traffic Safety Administration January 2007 Edition. Summary: Persons begin to feel and exhibit marijuana’s effects within 8-9 seconds after inhaling the smoke. The effects usually reach their peak within 10-30 minutes, and the effects generally continue for 2-3 hours. There are studies that indicate that the user may be impaired long after the euphoric effects have ceased. It is important to understand that some blood and urine tests may continue to disclose evidence of the use of marijuana long after the effects of marijuana have dissipated. That is because certain chemical tests do not seek to find THC itsef, but instead look for metabolites of THC, or chemical by-products. It can take as long as four hours for THC to appear in the urine in concentrations sufficient to trigger an immunoassay (50 ng/mL) following smoking. Some blood tests may disclose marijuana use for at least three days after smoking. Some urine test may indicate the presence of THC metabolites for 28-45 days. There are two important metabolites of THC. One of the metabolites is Hyroxy THC; this causes the user to feel euphoric so they are aware of the effects. Hydroxy TCH usually is eliminated from the blood plasma within six hours. The other important metabolite if Carboxy THC. There is no evidence at this time that the metabolite is psychoactive. Carboxy TCH may be found in the blood plasma for several days following marijuana use. Supra at XX1-2 - XX1-3.
  • 33. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Page 9 – MOTION IN LIMINE TO EXCLUDE EVIDENCE OF RETROGRADE EXTRAPOLATION WITHOUT PROPER FOUNDATION LAW OFFICES OF BRIAN COX 142 West 8 Avenueth Eugene, Oregon 97401 Telephone: (541) 683-7151 † Facsimile: (541) 485-7742 coxandassociates@coxassociates.info Citations to Additional Studies: “It is not possible to conclude anything about a driver’s impairment on the basis of his or her plasma concentrations of … THC-COOH determined in a single sample.” U.S. Department of Transportation Marijuana and Actual Driving Performance November 1993. p. 108. “The presence of THC–COOH thus does not necessarily imply recent use of cannabis or impairment. … [T]his metabolite, THC–COOH, can be assessed in body fluids for hours and days and is not a reliable indication of recent cannabis use or impairment. … [T]hese data indicate that recent cannabis use may increase crash risk, whereas, past use of cannabis as determined by the presence of THC–COOH in drivers does not.” Ramaekers et al. 2004. Dose related risk of motor vehicle crashes after cannabis use. Drug and Alcohol Dependence 73: 109-119. “[T]here is little scientific evidence to show that the detection of … THC-COOH in bodily fluids can be taken as proof of impairment in any circumstance.” Ramaekers et al. 2006. Cognition and motor control as a function of delta-9-THC concentration in serum and oral fluid: limits of impairment. Drug and Alcohol Dependence 8: 114-122. “Quantitation of THC-COOH can neither accurately predict the time of last cannabis use nor suggest any relationship between urine concentration and psychomotor performance.” Musshoff and Burkhard. 2006. Review of biologic matrices as indicators of recent or ongoing cannabis use. Therapeutic Drug Monitor 28: 155-163. Relating to Retrograde Extrapolation of Blood Alcohol Content Exhibit 3: Comparing Roadside With Subsequent Breath Alcohol Analysis And Their Relevance To the Issue Of Retrograde Extrapolation, Forensic Science International, 57 (1992) 193 - 201. Summary: Retrograde extrapolation applied to the data employing an assumed 0.15g/210 l/h yielded a small but significant overestimate of the actual known BAC from breath testing. Evidentiary analysis performed within two hours of driving will provide good estimates and certainly not overestimates, of the BAC existing at the time of driving and it appears that extrapolation may be unwarranted in these cases. Exhibit 4: The Metabolism and Pharmocokinetics of Alcohol in Man, J. Forens. Sci Soc (1977), 17, 49 Summary: Back extrapolation determinations of blood alcohol levels based on a single rate of decrease in concentration vs. a non-linear rate of decrease in concentration (particularly if low) must often yield estimates bordering on wild guesses. Exhibit 5: The Estimation of Blood Alcohol Concentration Widmark Revisted, Forensic Sci. Med. Pathol.: 3:1:33
  • 34. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Page 10 – MOTION IN LIMINE TO EXCLUDE EVIDENCE OF RETROGRADE EXTRAPOLATION WITHOUT PROPER FOUNDATION LAW OFFICES OF BRIAN COX 142 West 8 Avenueth Eugene, Oregon 97401 Telephone: (541) 683-7151 † Facsimile: (541) 485-7742 coxandassociates@coxassociates.info Summary: The simple Widmark calculation used by many experts results in a higher BAC than any of the other methods, whereas the other methods tend to agree with each other and not with Widmark. The primary reason for the elevated numbers obtained when using the Widmark ‘r’ value is that the other methods calculate ‘r’ based on measure parameters rather than relying on the average value obtained from a small group of individuals in 1932. Exhibit 6: Absorption, Distribution and Elimination of Alcohol: Highway Safety Aspects. Kurt Dubowski, PhD, Journal of Studies on Alcohol, Supplement No. 10, July 1985 Summary: A trend-line curve is markedly inappropriate or useless for attempts to engage in retrograde extrapolation, for, among others, three main reasons: (1) lack of knowledge about the timing of the alcohol consumption peak; (2) ignorance about the mathematical characteristics (e.g. linear, pseudo-linear, exponential); and the mean rate of change in the individual’s blood or breath alcohol elimination curve; and (3) unpredictable irregularities in the curve, especially short-term fluctuations from the best-fit trend line of the blood or breach alcohol curve. Supra @ 103. Most alcohol pharmocokinetics parameters are subject to a wide inter-subject variability, as exemplified by peak alcohol concentrations reached on ingestion of identical weight-adjusted doses, time to peak after end of drinking and rate of alcohol elimination from the blood. This great biological inter-subject variability, when combines with sex-, age and time-related differences, makes the blood alcohol on information in widely distributed alcohol consumption nomgrams and tables based on mean data inappropriate as a guide for the drinking behaviors of individuals. Supra @ 105. Breath and blood alcohol time curves are subject to short-term fluctuations from the trend line and other irregularities, and often do not follow the typical Widmark pattern. Supra @ 106. ===================================================================== Certificate of Service I certify that on this date I served the foregoing Motion in Limine to Exclude Evidence of Retrograde Extrapolation Without Proper Foundation upon the State by causing a true and complete copy of the same to be transmitted by facsimile to: Darwin Wuzright Facsimile Number - (123) 456-7891 Naught County District Attorneys Office Dated this 7 day of March, 2010.th COX & ASSOCIATES, LLC By: Brian D. Cox, OSB 902405 Of Attorneys for Miss Accused