Evidence-Based Policing Matrix
Groups – Ratcliffe et al. (2017)
Study Reference:
Location in the Matrix; Methodological Rigor; Outcome:
Groups; Focused; Proactive; Moderately rigorous; Effective
What police practice or strategy was examined?
One of the FBI’s Violent Gang Safe Streets Task Forces was established in Los Angeles to conduct a gang interdiction operation. The FBI-led task force included federal agents and local officers and operated in a specific geographic area where the gang operated. The interdiction focused on an intelligence gathering and surveillance approach to build information on the gang and then move to arrests, including all key members of the organizational structure, and seizing assets to dismantle the gang. The operation was in place for 12 months building the case before the day of the takedown. The takedown resulted in 23 federal indictments, 24 arrests on the day of the takedown, 26 warrants issued, and four probation/parole searches executed. A brief follow-up period involved cleaning 40 alleys in the area and a community resource day.
How was the intervention evaluated?
The gang targeted for the intervention was determined by the task force. The researchers identified a similar gang and gang territory to use as a comparison area for the study. Part 1 crime data for 80 months pre-intervention and 14 months post intervention were collected to measure crime trends in the treatment and control areas. Additionally, a two-block area was identified around the treatment area to measure any displacement effects of the intervention.
What were the key findings?
Controlling for pre-intervention trends in the target area as well as trends in the comparison area, the program reduced violence in the treatment area by 22%. The displacement analysis found that those benefits extended to the surrounding area. These violence reduction benefits persisted for at least the first nine months after the intervention, after which the trend continued to be positive but was no longer statistically significant.
What were the implications for law enforcement?
The findings indicate that targeted gang interventions involving proactive surveillance and investigation can effectively target the existing gang structure and significantly dismantle gang organizations. The authors suggest that maintaining those benefits for longer durations will likely require efforts targeting community characteristics that lead to individuals joining gangs or maintaining investigative police work to identify any new gang membership in the area.
Where can I find more information about this intervention, similar types of intervention, or related studies?