Effectiveness of Reform Efforts Focused on Police Use of Force and Complaints: A Systematic Review and Meta-Analysis
Police violence in the United States remains a pressing public concern, with more than 1,200 people killed by police in 2024 alone. Despite widespread calls for reform and the proliferation of policies and training programs designed to reduce excessive force, there is limited evidence on which strategies are most effective. Policymakers, practitioners, and communities continue to grapple with questions about what reforms truly work and under what conditions.
To help address this gap, AIR conducted a systematic review and meta-analysis of U.S.-based reforms—ranging from body-worn cameras and training programs to hiring standards, Department of Justice oversight, and court rulings.
Our analysis drew on 18 high-quality studies (half of which were randomized controlled trials) published between 2000 and 2021. Using advanced meta-analytic methods, we synthesized evidence across 27 reform interventions to examine impacts on both police use of force and citizen complaints.
Key Findings
Findings suggest that reforms are associated with modest reductions in use-of-force incidents (11% lower) and citizen complaints (18% lower), though these effects were not statistically significant overall. Importantly, effects differed by officer participation: reforms showed significant reductions in force and complaints when officers or departments volunteered to participate, but not when participation was mandatory. This points to the critical role of motivation and engagement in driving reform effectiveness.
These results underscore the need for future reform efforts to not only focus on the content of policies and training but also on strategies to foster officer buy-in, measure compliance, and support sustained engagement. By strengthening both program design and implementation, policymakers and practitioners can build reform approaches more likely to achieve meaningful reductions in harmful police–community encounters.
