1. Simulating Police Outcomes: A Framework for Understanding Policing Strategies John E. Eck University of Cincinnati Division of Criminal Justice Presentation at the meeting on Crime Hot Spots: Behavioral, Computational and Mathematical Models Institute for Pure and Applied Mathematics, UCLA January 29 - February 2, 2007

2. An Initial Thought..computer simulations are actually philosophical thought experiments, intuition pumps, not empirical experiments. They systematically explore the implications of sets of assumptions. Daniel Dennett

3. Barbarian Invasions and Crime Standard criminology is bankrupt A good invasion can help Mostly raids – uncooperative, naive, and short Taking the easy loot Leaving some methods but little insight Need to settle, interbreed, and stay Welcome Barbarians!

4. Introduction Simulating police is a subset of simulating crime Early simulations focused now discredited policing strategies Topics –Police Strategies – roles and effectiveness –Simulation Framework – 4 parts –Focused Policing –Problem-oriented Policing

5. Police Strategies & Evidence Standard ModelFocused CommunityProblem-oriented Focus generalspecific Range of Interventions Narrow – Law enforcement Diverse ineffective Patrolling Investigations Fast Response Hotspots patrols Repeat offender invest. Repeat victimization effective Partnering Public interactions Building support ambiguous Specificity Analysis Tailored interventions Evaluation effective Adapted from, Weisburd, D. & J.E. Eck 2004 “What Can Police Do to Reduce Crime, Disorder and Fear?” The Annals of the American Academy of Political and Social Science. 593: 42-65.

6. Strategies and Simulations Standard ModelFocused Community Problem-oriented Focus generalspecific Range of Interventions Narrow – Law enforcement Diverse Evidence suggests insufficient fecundity to be a central focus. Part of larger simulation. Potential for simulation, particularly first generation simulations. Simulation low utility due to lack of clarity of means and ends Simulations important for a) understanding problems; b) pre-testing interventions; and c) evaluating results.

7. 4 Requirements 1.Problem/Patterns (change) are outputs 2.Error modeling must be built in 3.Standard policing part of background 4.Model intervention mechanisms

8. Basic Parts of Police Simulations 1. Simulation of Problem/Pattern 4. Simulation of Problem Interventions 3. Simulation of Standard Operations Output Gods’ eye view of patterns Human eye view of patterns 2. Reporting/Recording Filter

9. Filtering & Calibration Crime event i occurrences Crime event i reports to police Crime events recorded and classified as i, j, k etc Everybody knows the dice are loaded. Everybody roles with their fingers crossed. Leonard Cohen “Everybody Knows” Results of valid sims of this May not reflect this

10. The Great Mystery of Crime Reporting ? Number of previous victimizations Probability of reporting this crime to the police A B C How does victimization experience influence peoples willingness to report crimes to the police?

11. Simulating Standard Policing 1. Simulation of Problem/Pattern 4. Simulation of Problem Interventions 3. Simulation of Standard Operations Output Gods’ eye view of patterns Human eye view of patterns 2. Reporting/Recording Filter

12. Standard Policing Vary density of police patrols Vary speed of response Vary offender removal settings Vary filter simulation settings

13. Simulating Focused Policing 1. Simulation of Problem/Pattern 4. Simulation of Problem Interventions 3. Simulation of Standard Operations Output Gods’ eye view of patterns Human eye view of patterns 2. Reporting/Recording Filter Sim. of crime analysis

14. Focused Policing Simulate a crime analysis function Detects hotspots Patrols respond to detected hotspots Vary sensitivity, error, speed, & intensity of analysis and patrols Create analogous arrangements for focusing on offender networks and repeat victims

15. Perceived Hotspots in Offender & Victim Spaces age income Links known Unknown links Commuting time

16. 1. Simulation of Problem/Pattern Simulating P-O Policing 4. Simulation of Problem Interventions Output Gods’ eye view of patterns Human eye view of patterns Sim. of problem analysis 2. Reporting/Recording Filter 3. Simulation of Standard Operations

17. Problem-oriented Problem Analysis simulation is a simulation of the problem simulation –Allows testing of various heuristics –Can be used to study knowledge limitations Range of interventions broad Mechanisms for interventions diverse Simultaneous multiple intervention points possible Can be applied to non-police interventions

18. Simulating POP vs Simulating Intervention Simulation of Problems Simulation of Problem Analysis Intervention Selection Planning & Evaluation Simulation of Problem Intervention simulation POP Simulation

19. Examples of Intervention Simulations Model of crowds used to simulate alternative parade routes (Batty 2005) Design street barricade arrangements based on crime and traffic flow models Experimentally vary place management intensity for landlord interventions Batty, M. 2005 Cities and Complexity: Understanding Cities with Cellular Automata, Agent-Based Models, and Fractals. Cambridge, MA: MIT Press.

20. Analysis Units in 3 Strategies Standard Model – No analysis: patrols wander or go to most recent crime Focused Policing – Analysis detects spatial-temporal cluster: patrol of clusters Problem-Oriented Policing – Analysis models problem: police address process

21. Conclusions Welcome Pay attention to existing evidence Pay attention to useful theories Pay attention to data errors Pay attention to forms of policing

22. A Final Cautionary Note Today's scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality. Nikola Tesla

23. Further Reading Center for Problem-Oriented Policing www.popcenter.org