This Essay investigates Chicago city-government policy responses to the four largest homicide waves in its history: 1920–1925, 1966–1970, 1987–1992, and 2016. Through spatial and historical methods, we discover that Chicago police and the mayor’s office misused data to advance agendas conceived prior to the start of the homicide waves. Specifically, in collaboration with mayors, the Chicago Police Department leveraged its monopoly over crime data to influence public narratives over homicide in ways that repeatedly (1) delegitimized Black social movements, (2) expanded policing, (3) framed homicide as an individual rather than systemic problem, and (4) exclusively credited police for homicide rate decreases. These findings suggest that efforts to improve violence-prevention policy in Chicago require not only a science of prevention and community flourishing but also efforts to democratize how the city uses data to define and explain homicide.

这篇文章调查了芝加哥市政府对其历史上四次最大的凶杀案的政策反应：1920-1925、1966-1970、1987-1992 和 2016。通过空间和历史方法，我们发现芝加哥警察和市长办公室滥用职权数据来推进在凶杀浪潮开始之前构想的议程。具体来说，芝加哥警察局与市长合作，利用其对犯罪数据的垄断，以反复（1）使黑人社会运动不合法，（2）扩大警务，（3）将凶杀案视为个人而不是比系统性问题，和 (4) 专门归功于警方的凶杀率下降。