1. PREDICTIVE POLICING
The Optimal Forager and the Missing Dimension
ERIC HALFORD MA

2. Origin of Thesis
Necessity - CSR and funding formula
Efficiency - Drive Towards Evidence Based Policing- How
do you apply science to policing to Enhance Use of
Resources
Effectiveness – How to Continue or Maintain
Unprecedented Reductions in Crime
Economy – Better Value for Money
Comprehensive performance management literature
review

3. The Literature
o Criminology, Psychology, Policing
o Problem Orientated Policing – Reduction In NHPTs – All But Ceased
o Hotspot Policing – Effective But Need To Evolve
o Intelligence Led Policing – 75% Reduction In Intelligence Sees Framework
Collapse
o Predictive Policing – Evolution Not Revolution
o Absence Of Literature On Predictive Policing
o A Lack Of Operational Empirical Literature Across Policing Academia

4. Predictive Policing
Increased Efficiency and Value For Money:
“With predictive policing, we have the tools to put
cops at the right place at the right time or bring other
services to impact crime, and we can do so with less”
(Gascon, 2009).

5. Predictive Policing
Disparate Attempts to Introduce Across The UK
Some Software Centric Approaches – i.e. PredPol
Predominately Adopted in The Form of Optimal
Forager/Near Repeat Victimisation
9 Potential Case Studies Identified

6. Predictive Policing
How The Research Was Done:
3 Wholesale Case Studies
20 + Interviews of Practitioners And Analysts
Access to Crime Records
Questionnaires
Hundreds of Pages of Quantitative Analytical Reports
*Caveat - Access Denied To Study Pilots Using Software Approaches I.E.
PredPol Which May Impact on Conclusions

7. The Optimal Forager
• Optimal Forager And Near Repeat – Same
Principles
• Pretext Is Simple – Criminals Behave As Foraging
Animals
• Foraging Animals Target Areas Low In Risk, High
in Reward – Food is Their Target
• Criminals Act in The Same Manner – Realisable
Property is Their Target

8. The Foraging Animal
Risk =
Energy expenditure
Travel Time
Distance
Processing Time

9. The Foraging Criminal
The Assumption is Criminals Behave As
Optimal Foragers
Risk = Travel, Distance, Victim Availability, Time To
Sell Stolen Property
BUT
How Do The Police Fit in? Capable Guardian
Fails to Adequately Address Serial Offending

10. Op Forager is
Fundamentally Flawed
Research Shows That All UK Implementations of
Op Forager Assumes a Two Tier Interaction
The Criminal is The Predator
The Victim is The Prey

11. Ecology Literature However Identifies It as a Three
Tier Interaction (Hugie, 1994 And Sih, 1998)
Predator (Police) – Prey (Criminal) – Resource
(Victim)
Why is This Important?

12. What Ecology Says
Its OK, Even They Forgot About The Predators!!
The Impact of Increased Predation Risk is
Consistently Overlooked (Lima, 2005)
Increased Predation on Foraging Animals Shows
That it Does Not Reduce Or Stop The Animals
Foraging (Verdolin, 2005)
It Forces The Forager To Alter Their Behaviour In a
Number of Ways (Lima, 2002)

13. Changes in Behaviour
1. The Forager Will Alter Their Selected Resource,
2. They Will Reduce The Handling Time
3. They Will Increase Their Vigilance In Response To Increased Predation,
Particularly On The Periphery Of Previously Foraged Areas (Kelley
Et Al, 2001)
4. Higher ‘Giving Up’ Rate By The Forager Before Ultimately Seeking A
New Foraging Patch (Kelly Et Al, 2001).
5. Forager May Also Choose To Begin Searching In Groups Which
Provides Additional Security And Early Detection Of Predators (Berkley,
2000)
6. They Will Switch The Foraging Patch (Engelhart And Muller-schwarze
1995; Epple Et Al. 1993; Pfister Et Al. 1990; Sullivan And Crump 1984)

14. Key Assumption
If It is Accepted That There is a Proven Assumption
That the Criminal Operates as a Forager Then Within
the Context of Policing the Behavioural Changes of
the Criminal Should Manifest Itself in a Number Of
Specific Ways (Halford, 2015)

15. Criminal Behavioural
Manifestations
1. The Criminal May Change The Type Of Target I.E. From Dwellings To
Business
2. Items That They Seek May Change To Ones That Have A Lower
Handling Time
3. The Criminal Will Become More Aware of Increased Police Presence.
As Such the ‘Giving Up’ Rate May Increase
4. Particularly Prevalent at the Edge of Patches or in This Context, The
Predicted 400m Prediction Zones.
5. They May Recruit Assistance – Social Contagion
6. Most Significantly, the Criminal Will Simply Change Patch and Switch
Their Activity From One Area to Another

16. The Result
Minimal, If Any, ‘Overall’ Crime Reduction Or
Prevention
If Crime Reduction or Prevention Does Occur it is
Only Likely to Be Small, Short Term And Geo-
Specific
Significant Levels of Crime Displacement Occurs
Can in Fact Increase Overall Crime if
Implemented Ineffectively

17. How to Combat
Behavioural Change?
It is Not a One Way Interaction
There Are Behavioural Changes That The Predator Can
Make
When A Predator Can Move Between The Area Of The
Preys Resource And Natural Habitat, It Directly Impacts
On The Prey’s Mortality And Negates Any Antipredator
Benefits Of Moving Beyond Their Habitat
(Werner and Gilliam, 1984 and Bouskilla, 1998)

18. What Does That Mean?
If The Police (Predator) Can Operate In Both The
Area of the Criminal’s (Prey) Home Or Base (Natural
Habitat) And The Area The Criminal Commits Crime
(The Foraging Patch) And Seeks Their Victims
(Resource)……..
……They Stand A Significantly Greater Chance Of
Apprehending Or Deterring Them Completely
(Increased Mortality)

19. How Can We Do That?
• Traditional Hotspot Policing AKA – Crime Spikes
• The Standalone Optimal Forager Predictive
Approach
• The Wider Hotspot ‘PredPol’ Approach
• Or, Something Entirely New?
• A Combined Predictive Model

20. TRADITIONAL OR PREDICTED HOTSPOT APPROACH
Traditional Hotspot
or Predicted Forager
Locality

21. Traditional or Predicted
Hotspot Approach
Both Cause Crime Displacement
Both Rely on Intelligence to Operate within the
‘Natural Habitat’
However, some UK forces have experienced up
to a 75% reduction in intel 2005-2015
Both End Up ‘Rounding Up the Usual Suspects’
Is the Current NIM Framework Even Effective
Anymore?

22. THE WIDER ‘PREDPOL’ HOTSPOT

23. The Wider ‘PredPol’
Hotspot
• Refers To Crime Displacement as a Myth
• Operates On The Assumption That There Are Two
Types of Crime Hot Spots That React Differently to
Increased Policing
• One That Relocates (Due To Crime Displacement)
• Another That Dissolves (Super Critical Hotspot)

24. ……”You can’t just go and suppress all those small
spikes in crime; you’re going to suppress the big hot
spot……the small spikes in crime that are out there in
the environment are ready to nucleate into a new one..
However, the larger, subcritical hot spots do not re-
emerge after increased policing”
(Brantingham, 2006)
Translated = Unpalatable. You Probably Need a Big
Budget And Lots of Resources Dedicated to Patrol
Saturation

25. A Combined Predictive
Model
EVOLUTION NOT REVOLUTION
Predicts Locality of Both Crime and Offender
Optimal Forager Crime Location Predictions
Geographical Profiling to Predict the Serial
Offenders Likely Home or Base
Purely Evidence Based and Scientific

26. GEOGRAPHICAL
PROFILING
DEFINITION
“An investigative technique used to
determine the most likely location of a
criminal’s residence based upon the
geographic location of crime sites”
(Prof. David L. Wiesenthal, 2012)

27. THE COMBINED PREDICTIVE MODEL

28. The Steps
Offences Committed
Crime Linkage Analysis Identifies Serial Offending and
Linked Crimes
Geographically Profile Linked Offences – Predict
Offenders Habitat
Optimal Forager Analysis – Predict Future Crime Area
Traditional Policing Techniques – Subsequent Use of
Resources To Target the Profiled Area and Suspects

29. The Predicted Result
Enhanced Focus on T&C of Finite Resources
Evidence Basis for Target Selection
Evidence Basis for Priority Offender Management
Greater ‘Overall’ Crime Reduction and Prevention
Potential

30. The Potential Blockers
Training is Key – Staff Must Understand the Theory
The Human Factor – Staff Must ‘Buy In’ for
Success
Senior Managers – Attitude and Support Will Make
it Stand or Fall

31. The Future
More Effective Ways to Link Crimes
Better Use of Big Data and Predictive Analytics
Predict Offenders Before They Offend
Intervention Pathways

32. SIMPLE'S!
ANY QUESTIONS?