The Philadelphia predictive policing experiment
Objectives This place-based, randomized experiment explored the impact of different patrol strategies on violent and property crime in microscale predicted crime areas. The experiment aimed to learn whether different but operationally realistic police responses to crime forecasts, estimated by a pre...
| Authors: | ; ; ; ; ; ; ; |
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| Format: | Electronic Article |
| Language: | English |
| Published: |
2021
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| In: |
Journal of experimental criminology
Year: 2021, Volume: 17, Issue: 1, Pages: 15-41 |
| Online Access: |
Volltext (Resolving-System) Volltext (Verlag) |
| Journals Online & Print: | Drawer...
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| Check availability: | HBZ Gateway |
| Keywords: |
| Summary: | Objectives This place-based, randomized experiment explored the impact of different patrol strategies on violent and property crime in microscale predicted crime areas. The experiment aimed to learn whether different but operationally realistic police responses to crime forecasts, estimated by a predictive policing software program, could reduce crime. Methods Twenty Philadelphia city districts were randomized to three interventions and one control condition. The three interventions comprised awareness districts (where officers were made aware of predicted areas on roll-call), marked car districts (where a marked patrol police car was dedicated to treatment areas), and unmarked car districts (a plain-clothes vehicle was dedicated to treatment areas). A business-as-usual approach represented the control condition in districts where staff had no access to the predictive software program. Two distinct 3-month phases examined crime outcomes for property and violent crime, respectively. Results The marked car treatment showed substantial benefits for property crime (31% reduction in expected crime count), as well as temporal diffusion of benefits to the subsequent 8-h period (40% reduction in expected crime count). No other intervention demonstrated meaningful crime reduction. These reductions were probably not substantial enough to impact city or district-wide property crime. Some violent crime results ran contrary to expectations, but this happened in a context of extremely low crime counts in predicted areas. The small grid size areas hampered achieving statistical power. Conclusions The experiment found reductions in property crime resulting from the marked car focused patrols. It also demonstrated the real-world challenges of estimating and preventing crime in small areas. |
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| ISSN: | 1572-8315 |
| DOI: | 10.1007/s11292-019-09400-2 |