Evidence-Based Policing Matrix
Micro Places – Braga et al. (1999)
Study Reference:
Location in the Matrix; Methodological Rigor; Outcome:
Micro places; Focused; Highly proactive; Very rigorous; Effective
What police practice or strategy was examined?
This study examined the effects of problem-oriented policing interventions on urban violent crime problems in Jersey City, New Jersey. The program and evaluation design followed the SARA model. The Jersey City Police Department (JCPD) and Rutgers researchers identified violent crime hot spots using robbery and assault incidents and citizen calls for service data. Each hot spot was defined as an intersection area including the intersection and its four adjoining street segments. Then, by analyzing official data sources and discussing problems with community members, the JCPD Violent Crimes Unit (VCU) investigated the source and extent of the violent crime problems and developed appropriate problem-oriented responses. As a result, 28 specific strategies were implemented across 12 treatment places that can be categorized as situational crime prevention interventions or as order maintenance interventions.
How was the intervention evaluated?
Twelve pairs of hot spots were selected for random allocation to the treatment or control group. The hot spots allocated to the treatment group received the problem-oriented policing intervention. The control hot spots group received the routine amount of traditional policing strategies including arbitrary patrol interventions and routine follow-up investigations by detectives. Crime incident report data and citizen emergency calls for service data were compared for six-month pre-intervention and post-intervention periods. Field observation data were also collected to detect changes in physical and social incivilities before and after the intervention. Further, a two-block catchment area was constructed around each of the 24 places to measure any displacement and diffusion effect.
What were the key findings?
The total number of criminal incidents and calls for service were significantly reduced at the treatment places relative to the control places. Specifically, significant reductions were observed for most disaggregated crime categories including robbery, property crime, street fights, and narcotics crimes. Although calls and incident reports for disorder did not decline significantly, onsite observations suggested that physical and social disorder were significantly reduced at the treatment locations. No evidence was found for displacement.
What were the implications for law enforcement?
The authors suggest that the problem-oriented policing program was effective in reducing crime and disorder at violent crime hot spots with little evidence of displacement.
Where can I find more information about this intervention, similar types of intervention, or related studies?