Policing Predicted Crime Areas: An Operationally-Realistic Randomized, Controlled Field Experiment, Philadelphia, Pennsylvania, 2015-2016

The Philadelphia Predictive Policing Experiment was a place-based, randomized control trial to study the impact of different patrol strategies on violent and property crime in predicted crime areas. The experiment's goal was to learn whether different operationally-realistic police responses to crime forecasts, estimated by a predictive policing software program, would reduce crime. Specifically, the study tested whether greater awareness among general duties patrol officers of the predicted crime areas would be sufficient to deter crime, whether a dedicated uniform patrol attendance in predictive areas would increase visible police presence sufficiently in the local area to deter crime, or if dedicated plain-clothes units performing surveillance and unmarked patrol would increase interdiction and offender incapacitation sufficiently to reduce crime. With support of the Philadelphia Police Department, the study took place over two, three-month periods between 2015 and 2016.

费城预测性警务实验（Philadelphia Predictive Policing Experiment）是一项基于地域的随机对照试验，旨在探究不同巡逻策略对预测犯罪区域内暴力犯罪与财产犯罪的影响。本实验的核心目标是验证：针对由预测性警务软件（predictive policing software）生成的犯罪预测，采用不同具备实战可行性的警务响应方式是否能够减少犯罪。具体而言，本研究检验了三类警务模式的有效性：一是提升常规巡逻警员对预测犯罪区域的知晓程度，是否足以威慑犯罪；二是在预测犯罪区域部署专属着装巡逻警力，是否能充分提升当地可见警务存在感以达成犯罪威慑；三是安排便衣执法单位开展监视与无标识巡逻，是否能充分提升犯罪拦截效率与犯罪者犯罪能力剥夺效果，进而实现犯罪减少的目标。在费城警察局（Philadelphia Police Department）的支持下，本实验于2015年至2016年间分两个为期三个月的阶段开展。