The Philadelphia Foot Patrol Experiment

Abstract

During early 2009, violent crime reports were drawn from the incident database of the Philadelphia Police Department for 2006, 2007 and 2008. Violent crime here is defined as homicide, aggravated assault, and robberies not occurring indoors. Incidents were weighted so crimes from 2008 counted 1.0, 2007 crimes counted 0.5, and 2006 crime events counted 0.25. In this way, more recent events had greater relevance in the creation of the target locations for 2009, but summary values retained a portion of the long-term hotspot component.