Facilitating police reform: Body cameras, police-involved homicides, and law enforcement outcomes
研究分析了美国593个警察机构的数据，发现执法记录仪减少警察涉入凶杀案的效果因地区和机构政策而异，且未对整体逮捕率或犯罪率产生负面影响。
Body-worn cameras (BWCs) have emerged as a crucial reform to restore police legitimacy. However, there remains limited evidence on the conditions under which BWCs reduce use of force and affect broader agency-wide outcomes. Using a quasi-experimental event study design, I analyze data from 593 U.S. police agencies to estimate the effects of BWC adoption. I find that reductions in police-involved homicides are heterogeneous—concentrated in regions with higher prior levels of such incidents and in agencies with stricter activation requirements, with no measurable change in low-incident regions or agencies with weaker policies. This study also provides the first evidence on agency-wide outcomes, finding no significant trade-offs in overall arrest or crime rates. These findings offer insight into when BWCs are most likely to enhance police accountability and performance.