Predictions Put Into Practice: a Quasi-experimental Evaluation of Chicago's Predictive Policing Pilot

Content Advisory

Please be aware that this content contains descriptions of violence that may be distressing to some viewers.
NCJ Number
251297
Journal
Journal of Experimental Criminology Volume: 12 Issue: 3 Dated: September 2016 Pages: 347-371
Date Published
September 2016
Length
27 pages
Annotation

This study identified the impact of a pilot program on individual-level and city-level gun violence, and tested possible drivers of results.

Abstract

In 2013, the Chicago Police Department conducted a pilot of a predictive policing program designed to reduce gun violence. The program included development of a Strategic Subjects List (SSL) of people estimated to be at highest risk of gun violence who were then referred to local police commanders for a preventive intervention. The SSL consisted of 426 people estimated to be at highest risk of gun violence. ARIMA models were used to estimate impacts on city-level homicide trends, and propensity-score matching to estimate the effects of being placed on the list on five measures related to gun violence. A mediation analysis and interviews with police leadership and COMPSTAT meeting observations helped in understanding what is driving results. Individuals on the SSL were not more or less likely to become a victim of a homicide or shooting than the comparison group, and this was further supported by city-level analysis. The treated group was more likely to be arrested for a shooting. It is not clear how the predictions should be used in the field. One potential reason why being placed on the list resulted in an increased chance of being arrested for a shooting is that some officers may have used the list as leads to closing shooting cases. The results provide for a discussion about the future of individual-based predictive policing programs. (Publisher abstract modified)

Grant Number(s)
2009-IJ-CX-K114
Agencies
NIJ-Sponsored
Publication Type
Research (Applied/Empirical)
Program/Project Evaluation
Date Published: September 1, 2016