The Peacemaker Fellowship and Urban Gun Violence in Richmond, California

Importance: Firearm violence is a leading cause of premature death and disability in the US. Increasingly, public health approaches to prevent gun violence are being implemented to reduce its social and medical costs. A previous evaluation of the Peacemaker Fellowship found it was associated with a 43% reduction in firearm homicides and assaults through 2016. However, evidence about effectiveness beyond this period remains limited. Objective: To examine the long-term associations between the implementation of the Office of Neighborhood Safety's Peacemaker Fellowship and fatal and nonfatal firearm assaults in Richmond, California. Design, Setting, and Participants: This cross-sectional study introduces a systematic donor selection process to the augmented synthetic control model. Richmond was compared with a weighted composite of US cities similar to Richmond on pretreatment annual crime and demographic characteristics (synthetic Richmond) between June 2010, and December 2024. Federal Bureau of Investigation Uniform Crime Reporting fatal and nonfatal firearm assault data from January 1996, to December 2024 were analyzed. Intervention: The Peacemaker Fellowship is a public-health oriented gun violence reduction program implemented by the Office of Neighborhood Safety in Richmond since June 2010. The Fellowship is an intensive 24-month program during which street outreach workers recruit individuals at the center of gun violence, offer them supportive wraparound services, and interrupt street conflicts. Main Outcomes and Measures: The change in combined quarterly counts of fatal and nonfatal firearm assaults. The hypothesis was formulated before data collection. Results: The Peacemaker Fellowship was associated with a statistically significant mean quarterly reduction of 78.39 (95% CI, 34.24-128.48) fatal and nonfatal firearm assaults relative to our synthetic counterfactual, representing a 61.47% reduction during 14 years of implementation. Descriptive subperiod summaries suggest that the reduction was sustained and deepened as implementation was sustained, increasing from a mean reduction of 49.2% during the initial phase (2010-2016) to 66.3% during the postexpansion period (2017-2024). Conclusions and Relevance: In this cross-sectional research study of the Peacemaker Fellowship, the program was associated with a significant reduction in fatal and nonfatal firearm assaults during 14 years of implementation. The analysis also suggests that beneficial outcomes may have increased over time. The Peacemaker Fellowship may be an effective strategy for reducing firearm violence, highlighting the importance of sustaining investments in community violence interventions.