Which Police Departments Make Black Lives Matter?

Black Lives Matter (BLM) has gained support across racial lines and considerable financial backing. Yet it is unclear whether social science has responded with research likely to save Black lives. To encourage more applied research and related public discussion, we rank police departments in the 50 largest U.S. cities by their effectiveness in keeping homicides low and not taking civilian lives, while adjusting for poverty, which makes policing more difficult. We find enormous variation in police performance and offer qualitative evidence that this reflects organizational practices. We conclude with ideas for reform.