Research on Groups


Groups – Interventions which target gangs or other co-offenders (individuals who offend in concert). Note that any study targeting groups is included here, regardless of the level at which the results were analyzed (e.g., individuals, neighborhoods).

 Rigor: M=Moderately Rigorous; R= Rigorous; VR=Very Rigorous
 Y-axis: F=Focused and Tailored; G=General
 Z-axis: R=Reactive; P=Proactive; H=Highly Proactive
 Dots: Black=Effective; Gray=Mixed Results; White=No Evidence of Effect; 
       Red=Backfire effect
Intervention and Findings
Result Rigor Y-Axis Z-Axis
Ariel et al. (2019) Proactive engagement of prolific offenders led to lower offending in treated groups full-circle R F HP
Braga et al. (2001) Operation Ceasefire was associated with significant reductions in youth homicide victimizations, shots-fired calls for service, and gun assault incidents. full-circle M F HP
Braga (2008) Pulling levers intervention associated with significant decline in monthly gun homicide full-circle M F HP
Braga et al. (2008) Pulling levers intervention associated with significant decline in monthly gun homicide and gun-related assault full-circle M F HP
Braga et al. (2014) Operation Ceasefire associated with significant reduction in gang-related shootings full-circle R F HP
Bynum & Varano (2003) Aggressive patrol and order maintenance anti-gang initiative associated with substantial reported crime decreases in two target precincts full-circle M G P
Corsaro & Engel (2015) Focused deterrence strategy targeting violent gangs led to significant decreases in various measures of violent crime full-circle M F HP
Engel et al. (2013) Focused deterrence significantly reduced group/gang-member-involved homicides and violent firearm incidents full-circle M F HP
Fox & Novak (2018) Focused deterrence targeting violent offenders significantly reduced homicides and gun-related assaults during the first year of the intervention full-circle M F HP
Fritsch et al. (1999) (curfew) Truancy and curfew enforcement associated with reduction in gang violence full-circle M F P
McGarrell et al. (2006) A “lever-pulling” strategy was associated with a 34.3% reduction in the monthly homicide rate full-circle M F HP
Ratcliffe et al. (2017) Gang interdiction operation led to a 22% violence reduction in the area where the gang operated full-circle M F P
Ridgeway, Grogger, et al. (2019) Gang injunctions were estimated to reduce total reported crime by 5% in the short term (5 years), and 18% over the long term (27 years). full-circle R F P
Cahill et al. (2008) Gang reduction program led to decrease of gang-related incidents in the target area, but similar decrease observed in the comparison area grey-circle M F P
Decker & Curry (2003) Curfew and gun enforcement anti-gang initiative leads to a very limited significant crime change in target neighborhoods empty M F HP
Fritsch et al. (1999)(saturated patrol) Undirected, saturated patrol has no impact on crime empty M G P