The Philadelphia Foot Patrol Experiment

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 may spark a revision of a long-held view of police patrol.

Since the 1980s, it has long been the opinion of many police and criminology researchers that police foot patrols can 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 suggest that a more positive view of intelligence-led targeting of foot patrol officers may be warranted.

On the invitation of the Philadelphia Police Department, police and academic researchers worked together to plan the Philadelphia Foot Patrol Experiment as a randomized control trial. 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 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 comparison or a target area.

Officers generally patrolled in pairs with two pairs assigned to each foot patrol. They worked from Tuesday morning to Saturday night in two shifts (10am to 6pm, 6pm to 2am). 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 incident detections increased 15%
  • Pedestrian stops increased 64%
  • Vehicle stops increased 7%
  • Arrests increased 13%

 The reduction in violence indicates the foot patrols prevented 53 violent crimes during the summer.


This project won the 2010 IACP Excellence in Law Enforcement Research Award [details].


Look for future findings on our mixed-method study of foot patrol dosage, policing style, and management approach.

Click on the 'Research brief (pdf)' link on the right for a 3-page research summary.


Click on the 'Draft of full academic paper (pdf)' link on the right for the article in 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.


Long-term effects study 

Recent research by Evan Sorg, Cory Haberman, Jerry Ratcliffe and Liz Groff has examined the long-term impacts of the Philadelphia Foot Patrol Experiment to determine what happened after the experiment was over. Results showed that beats that were in place beyond three months had diminishing effects during the experiment, an effect not seen with the shorter term beats. Foot patrol beats returned to their pre-experiment crime levels once the foot patrol experiment was concluded. These findings have implications for integrating foot patrol with longer-term strategies.


These findings are published in the journal Criminology. Full citation: Sorg, E.T., Haberman, C.P, Ratcliffe, J.H and Groff, E.R. (2013) Foot Patrol in Violent Crime Hot Spots: Longitudinal Impacts of Deterrence and Post-Treatment Effects of Displacement. Criminology, 51(1): 65-102.

Use links to right for one page summary and the draft of the full paper.


Relationship between foot and car patrol study 

The question of how foot patrol affected the car patrol officers in which the foot beats were embedded is examined here.  Liz Groff, Lallen Johnson, Jerry Ratcliffe and Jen Wood delve into official data describing the activities of foot and car patrol officers.  They find noticeable differences in the activities of the two types of patrol.  Foot patrol is more likely to conduct pedestrian stops and deal with disorder and drug offenses while car patrol handled the vast majority of reported crime incidents. Police managers and researchers are advised to consider the impact of new strategies on the dominant patrol style.  Co-production of community safety among officers assigned to different patrol styles is an under-researched area with potential for improving the success of crime reduction efforts through better internal coordination of police resources.

These findings are published in the journal Policing: An International Journal of Police Strategies and Management. Full citation. Groff, E.R., Johnson, L., Ratcliffe, J.H. and Wood, J. (2013) Exploring the relationship between foot and car patrol in violent crime areas. Policing: An International Journal of Police Strategies and Management, 36(1): 119-139.

Use link to the right for a draft of the full paper.


Qualitative field observation study 

A recent paper by Jen Wood, Evan Sorg, Liz Groff and Jerry Ratcliffe reports on field observations of foot patrol officers involved in the experiment. The observations were designed to capture officers' perceptions of and experiences with the foot patrol function. The research found that officers developed extensive local knowledge of their beat areas, and were reflective agents with varying styles. They had to negotiate the tension between 'real police work' and the 'reassurance' function of foot patrol. They exerted spatial control through a repertoire of techniques which depended in part on officer style. We also learned that in some ways, the experimental nature of the intervention clashed with the common sense judgment of officers, including the need to adapt policing practices to changing criminal behavior. This research helps to highlight the value of qualitative research for experimental designs, and reinforces the need to integrate line officer knowledge in the design of place-based interventions.


These findings are published in the journal Policing and Society. Full citation:
Wood, J., Sorg, E.T., Groff, E.R., Ratcliffe, J.H. and Taylor, C.J. (2013) Cops as treatment providers: Realities and ironies of police work in a foot patrol experiment. Policing and Society: An International Journal of Research and Policy. DOI:10.1080/10439463.2013.784292.

Use link to the right for a draft of the full paper.

Related faculty
Jerry Ratcliffe

Elizabeth Groff

Jennifer Wood