Evidence-Based Policing Matrix

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Groups – Braga et al. (2001)

Study Reference:

Braga, A. A., Kennedy, D. M., Waring, E. J., & Piehl, A. M. (2001). Problem-oriented policing, deterrence, and youth violence: An evaluation of Boston’s Operation Ceasefire. Journal of Research in Crime and Delinquency, 38(3), 195-225.

Location in the Matrix; Methodological Rigor; Outcome:

Groups; Focused; Highly Proactive; Moderately Rigorous; Effective

What police practice or strategy was examined?

The study evaluated Operation Ceasefire, a problem-oriented policing and pulling lever strategy implemented in 1996 aimed at reducing youth homicide and youth firearms violence in Boston. Operation Ceasefire included two main elements: (1) a direct law-enforcement attack on illicit firearms traffickers supplying youth with guns and (2) an attempt to generate a strong deterrent to gang violence. The second element, known as the “pulling levers” strategy, involved reaching out directly to gangs, putting gang members on notice that offenders face certain and serious punishment for gang violence, and “pulling every lever” legally available when violence occurred. At the same time, efforts from various social and government organizations were made to provide resources and service to help youth escape the gang lifestyle.

How was the intervention evaluated?

The study evaluated the intervention with a time-series design. The main outcome variable was the monthly number of homicide victims ages 24 and younger between January 1991 and May 1998. The study also examined the monthly counts of citywide shots-fired citizen calls for service and gun assault incident reports in an active district from January 1991 to December 1997. In addition, the authors evaluated the intervention using a quasi-experimental design comparing youth homicide trends in Boston to 39 other large U.S. cities from January 1991 to December 1997.

What were the key findings?

The simple pre/post comparison of time-series data suggested statistically significant decreases in the monthly number of youth homicides (63%), reported gun incidents in the target district (25%), and citywide shots-fired calls for service (32%) in Boston. The quasi-experimental evaluation suggested that the reductions in Boston were significantly larger than those in most other cities, and that the large and abrupt changes that characterized the reduction in Boston differed from those of other American cities.

What were the implications for law enforcement?

The authors suggest that problem-oriented policing can be effective in controlling crime and disorder problems. In particular, the pulling levers strategy with cooperation from communities and with a more focused deterrence approach can be used to deal with chronic youth gang problems.

Where can I find more information about this intervention, similar types of intervention, or related studies?