Evidence-Based Policing Matrix
Groups – Papachristos and Kirk (2015)
Study Reference:
Location in the Matrix; Methodological Rigor; Outcome:
Groups; Focused; Proactive; Moderately Rigorous; Effective
What police practice or strategy was examined?
This study evaluated Chicago’s Group Violence Reduction Strategy (VRS), which involved a series of “call-ins” with gang members, to reduce gun violence. Police, researchers, and gang experts initially analyzed shooting patterns to specifically narrow the focus to individuals and groups most involved in shootings. Call-ins consisted of one-hour-long meetings with 15-20 individuals affiliated with gangs and were held in places of civic importance, such as a park, library, or school. These call-ins were divided into three different sections that emphasized both focused deterrence and procedural justice: (1) an enforcement component, (2) a community moral voice, and (3) a social service component. The enforcement component was led by a federal partner, who explained how federal statutes could be leveraged against the gang and stressed the deterrent aspect of the program. The community voice usually came from someone who had a family member harmed by gun violence. The social services component offered help and assistance from a case worker to those who wanted it. A total of 18 call-in meetings were held in Chicago between August 17, 2010, and December 31, 2013, with 149 gang factions (of 858 recognized across the city) having had at least one member in attendance. In total, 438 unique individuals attended a call-in during the intervention.
How was the intervention evaluated?
Due to the intervention’s focus on a subset of all gangs within the city, the authors used propensity score matching to compare the shooting behaviors of gang factions who were part of the program (i.e., treated factions) with factions similar in key characteristics (e.g., demographics, size, level of organization, geographic territory) who were not part of the program. Specifically, the authors compared the shooting behavior of treated groups (as either victim or perpetrator) in the 12 months after call-in attendance with the shooting behavior of matched control groups during the same 12-month period. Data on arrests, homicide, and nonfatal shootings provided by the Chicago Police Department covered the period from January 1, 2006, to March 31, 2014.
What were the key findings?
Gang factions attending a call-in were involved in 0.36 shootings in the 12-month period after the call-in, on average, while control factions were involved in 0.46 shootings during the same period. This equates to a 23% reduction in shootings after call-in attendance. Additionally, the authors reported that call-in attendance led to a 32% reduction in the likelihood of fatal or nonfatal victimization in the observation period but found no significant effect on known offending. However, given the heightened scrutiny the treated factions faced, any offending would be more likely to lead to an arrest. Therefore, the lack of significant difference between the groups at least suggests treated factions were no more likely than control factors to be involved in shootings and may have even been less likely, but just more likely to be caught.
What were the implications for law enforcement?
The call-in approach to violence reduction and efforts to get the right message to the right groups in a timely, just, and fair manner show promise for reducing gun violence. The VRS provides one way to intervene in the street dynamics that drive gun violence. Moreover, these programs achieve a significant reduction in crime while subjecting smaller, more focused groups to criminal justice intervention than net-widening policies like “stop and frisk.”
Where can I find more information about this intervention, similar types of intervention, or related studies?