Evidence-Based Policing Matrix
Neighborhood – Bynum et al. (2014)
Bynum, T. S., Grommon, E., and McCluskey, J. D. (2014). Evaluation of a Comprehensive Approach to Reducing Gun Violence in Detroit. Final Report submitted to the National Institute of Justice.
Location in the Matrix; Methodological Rigor; Outcome:
Neighborhoods, Focused, Proactive; Moderately Rigorous; Effective
What police practice or strategy was examined?
This study examines a Project Safe Neighborhoods (PSN) initiative implemented in Detroit. PSN involves multiagency task forces which include members from local, state, and federal law enforcement along with representatives from correctional agencies particularly probation and parole. The PSN model generally includes five key components: partnerships, a strategic problem-solving plan, training, outreach, and accountability. In the Detroit PSN, the central element of the intervention was case reviews of offenses committed with firearms by serious felons followed by vigorous enforcement. All firearms arrests were reviewed by key team members (US Attorneys, ATF, law enforcement, prosecutors) to determine priorities, and the working group also exchanged information and data regarding gangs and gun activity in the area.
How was the intervention evaluated?
Weekly totals of shooting victimizations in each of the six patrol districts were tabulated from January 1, 2006 through the week of March 23, 2008. A total of 117 weekly observations were recorded from each district. Thirty-nine weeks between October 1, 2006 and June 30, 2007 constituted the intervention period. A time series analysis was conducted.PSN was implemented in one treatment district. The remaining five districts were intended as control groups, however one district was excluded as a control site because it adopted a PSN-like program during portions of the observation periods.
What were the key findings?
Overall there was a small but statistically significant effect of the PSN activities on shooting victimizations. The district in which PSN was implemented had a reduction of 1.4 shooting victimizations per week compared to the pre-intervention period. During the post project period, shootings again increased, but not to the pre-project level. A series of t-tests revealed that the decline in fatal and non-fatal shootings was significant in the project period, while changes in other districts were not. However, analysis that included the post project period indicated that there was a decay of these effects over time to eventually return to near pre- intervention levels. It is important to note that when the project was operating at its peak levels of intensity, there was on average a reduction over this 39 week period of one shooting per week.
What were the implications for law enforcement?
The results suggest that targeted enforcement of serious felons committing gun crime and the working-group approach of PSN can lead to a modest decline in gunshot victimization. However, the best effects occur when the project was most active; maintaining these reductions after intensive enforcement activity may be difficult.
Where can I find more information about this intervention, similar types of intervention, or related studies?
- All studies in the Matrix on neighborhoods
- CEBCP Congressional Briefing on Reducing Gun Violence
- CEBCP Page on Directed Patrol to Reduce Gun Violence
- Police Strategies for Reducing Gun Violence
- One pager – Impact of PSN on Violent Crime
- One pager – PSN A national strategy to locally address gun violence
- CrimeSolutions Focused Deterrence Practice Profile
- Pulling Levers Systematic Review
- COPS Office Pulling Levers Review
- Project Safe Neighborhoods – Bureau of Justice Assistance
- Project Safe Neighborhoods – Michigan State University