The Philadelphia Foot Patrol Experiment was a major research collaboration between the Philadelphia Police Department and researchers in the Department of Criminal Justice involving over 200 police officers on foot beats around some of the city’s most violent corners.
Since the 1980s, it had long been the opinion of many police and criminology researchers that police foot patrols improve community perception of the police and reduce fear of crime, but they don’t prevent actual crime. Results from the Philadelphia Foot Patrol Experiment suggested a more positive view of intelligence-led targeting of foot patrol officers to violent crime hot spots.
On the invitation of the Philadelphia Police Department, police and academic researchers worked together to plan the Philadelphia Foot Patrol Experiment as a randomized and controlled field experiment. With the resources to patrol 60 locations, researchers identified the highest violent crime corners in the city, using data from 2006 to 2008. Police commanders then designed 120 foot patrol areas around these corners, and stratified randomization was used to assign pairs of foot patrols with similar crime rates as either a control or a target area.
Officers patrolled in pairs with two pairs assigned to each foot patrol. They worked from Tuesday to Saturday in two shifts (10am to 6pm, 6pm to 2am) during the summer of 2009. After three months, relative to the comparison areas, violent crime decreased 23%. Official records of police activities during the intervention period reveal the following in the target areas: Drug‐related detections increased 15%, pedestrian stops increased 64%, vehicle stops increased 7%, and arrests increased 13%. Even with some crime displacement to nearby locations, analysis indicated that the foot patrols prevented 53 violent crimes during the summer. This project won the 2010 Excellence in Law Enforcement Research Award from the International Association of Chiefs of Police and the Outstanding Experimental Field Trial Award from the American Society of Criminology’s Division of Experimental Criminology.
The experiment results were reported in the journal Criminology. The full citation is: Ratcliffe, J. H., Taniguchi, T., Groff, E.R., & Wood, J. (2011). The Philadelphia Foot Patrol Experiment: A randomized controlled trial of police patrol effectiveness in violent crime hotspots. Criminology, 49(3), 795-831.
A three-page research summary is also available.