Braga et al. (1999)
This randomized controlled trial evaluates the impact of problem oriented policing (aimed at initiatives that modify places, routine activities, and situations that promote violence) in New Jersey. The results of the impact evaluation support the growing body of research that asserts focused police efforts can reduce crime and disorder at problem places without causing crime problems to displace to surrounding areas.
Twenty-four high-activity, violent crime places were matched into 12 pairs. One member of each pair was allocated to treatment conditions in a randomized block field experiment. Patrols in treated places were instructed to scan the place, analyze risk factors, respond to specific issues, communicate with local residents, and developed situational interventions to address these issues.
The other members of the pairs did not receive treatment.
1) The total number of criminal incidents and the total number of citizen calls for service were significantly reduced at the treatment places relative to the control places. 2) All the crime type categories at the treatment places were reduced to varying degrees compared to control places.