Braga, A. A., Hureau, D. M., & Papachristos, A. V. (2012). An ex post facto evaluation framework for place-based police interventions. Evaluation review, 35(6), 592-626.
Location in the Matrix; Methodological Rigor; Outcome:
Micro places, Focused, Highly Proactive; Rigorous; Effective
What police practice or strategy was examined?
This study evaluated the Safe Street Teams (SST) program implemented by the Boston Police Department (BPD) in Jan 2007 to control violent crime hot spots using community and problem-oriented policing intervention. A team of one sergeant and six patrol officers were assigned to each of the targeted 13 violent crime hot spots to implement the program. The SST officers applied problem-oriented policing and worked with community members and local merchants in defining and responding to identified problems in the hot spot areas. During the two-year study, officers implemented around 400 strategies across the hot spots. Depending on each location’s problems, these included situational crime prevention interventions, enforcement interventions, and social service interventions.
How was the intervention evaluated?
The authors compared the violent index crime trends in the 13 targeted hot spots to trends in similar hot spots that were matched on several features and that did not receive the intervention. These features included the 2006 violent index crime counts, whether the street unit was a street segment or an intersection, neighborhood disadvantage in the surrounding U.S. Census block, and the number of street units that experienced three or more 2006 violent Index crimes in the surrounding U.S. Census block. A two-block catchment area was selected to measure the displacement and diffusion effects of the intervention.
What were the key findings?
This evaluation suggested that the SST program was associated with a statistically significant 17% reduction in violent Index crimes in the treatment areas relative to the control areas. Most of this reduction in violent crimes was driven by a large 19% reduction in robbery incidents, with a smaller 15% reduction in aggravated assault incidents. No evidence was found for crime displacement.
What were the implications for law enforcement?
The authors suggest that the problem-oriented policing framework with a community coproduction model and a situational crime prevention approach is effective in tackling violent crime hot spots without displacement.
Where can I find more information about this intervention, similar types of intervention, or related studies?