Evidence-Based Policing Matrix
Groups – Sierra-Arevalo et al. (2017)
Study Reference:
Location in the Matrix; Methodological Rigor; Outcome:
Groups; Focused; Proactive; Rigorous; Effective
What police practice or strategy was examined?
This study evaluated Project Longevity, a statewide focused deterrence gun violence reduction strategy piloted in New Haven, Connecticut, beginning in late 2012. The project started with a group audit, in which local law enforcement provided their insight and expertise on the active street groups in New Haven, their members, the activities these individuals engage in, and relational data detailing the network of feuds and alliances between groups. This process also involved a review of shooting and homicide incidents designed to assess which groups were most actively engaged in gun violence and the circumstances surrounding individual shooting events. This initial analysis identified 52 unique groups with 440 members operating within New Haven. Using these data, project staff invited members from some of the most violent groups to “call-ins,” in which law enforcement, social service providers, and community members met with group members to deliver three key points to attendees: (1) a community moral message against gun violence, (2) a law enforcement message about the consequences of further violence, and (3) an offer for help for those who want it. Call-ins lasted an hour and took place within New Haven’s City Hall. A total of six call-in meetings were conducted between November 2012 and June 2014.
How was the intervention evaluated?
Due to the intervention’s non-randomized and highly focused design, nearly all the groups identified in the project’s first phase had participated in at least one call-in, leaving no comparison groups within New Haven. Therefore, the authors compared aggregated monthly counts of shootings and homicides in New Haven to Hartford, Connecticut, a nearby city that did not receive the treatment. Data on both fatal and non-fatal shootings were provided by the New Haven and Hartford Police Departments for the period between January 2011 and April 2014, resulting in a 40-month time series for each city with Project Longevity active in the last 18 months of the time series.
What were the key findings?
Despite noting a preexisting downward trend in shootings and homicides in both New Haven and Hartford, the authors found that Project Longevity was associated with 2.4 fewer total shootings (both fatal and non-fatal) per month, 4.6 fewer group member-involved (GMI) incidents and 3.1 fewer possible-group member-involved incidents For this study, GMI incidents included both fatal and non-fatal shootings in which the police detected the involvement of a known street group offender as a victim or an offender during their shooting review/investigation.
What were the implications for law enforcement?
The authors suggest their findings bolster the case for implementing similar focused deterrence strategies outside of just major cities, while recognizing that the strategy must be adapted and customized to the unique distribution and structure of street groups in each city.
Where can I find more information about this intervention, similar types of intervention, or related studies?