Research Summary This study uses a quasi‐experimental design to evaluate the efficacy of Chicago's Group Violence Reduction Strategy (VRS), a gun violence reduction program that delivers a focused‐deterrence and legitimacy‐based message to gang factions through a series of hour‐long “call‐ins.” The results suggest that those gang factions who attend a VRS call‐in experience a 23% reduction in overall shooting behavior and a 32% reduction in gunshot victimization in the year after treatment compared with similar factions. Policy Implications Gun violence in U.S. cities often is concentrated in small geographic areas and in small networks of group or gang‐involved individuals. The results of this study suggest that focused intervention efforts such as VRS can produce significant reductions in gun violence, but especially gunshot victimization, among gangs. Focused programs such as these offer an important alternative to broad‐sweeping practices or policies that might otherwise expand the use of the criminal justice system.