Despite the increase in the policing of high-crime “hotspots” in a number of major U.S. cities, and the evidence of its effectiveness, there has been surprisingly little research on what police officers should actually do when patrolling those areas. The Philadelphia Police Department in Pennsylvania and its research partners in the Department of Criminal Justice at Temple University sought to address this limitation in the knowledge base through a randomized controlled study examining the impacts of three different police strategies in violent crime hotspots.
http://www.cna.org/sites/default/files/research/Philadelphia_Site_Spotlight.pdf
