Mapping Police Violence, a research collaborative associated with the Black Lives Matter movement, has released a report on killings by police in the past year. The news is bleak. According to the report, in 2015 police departments in the United States killed at least 1,152 people between January 1 and December 15. Nearly one in four of those people was killed in one of America’s 60 largest cities. The report found that the rate of police killings had little to do with population size or crime rates — New York, the largest city in the United States, ranked low on police department killings. Neither do crime rates have much effect. The report found that over the past few years, “police departments in high-crime cities such as Detroit and Newark have consistently killed fewer people per population than police departments in cities with much lower crime rates such as Austin, Bakersfield, and Long Beach.” The saddest findings of all? In 14 cities, every single person killed by the police was Black. The end-of-the-year report is the culmination of a year of documentation planned and organized by leaders in the Black Lives Matter movement. Sadly, there is a good chance the data underestimates the effect of police violence, as the collection of information regarding killings by police is incomplete. The report also does not include killings by vigilantes or security guards, unless they are off-duty officers. Despite all the hindrances, the writers are hopeful that the report will bring some quantitative clarity to a very real social issue. “We hope these data will be used to provide greater transparency and accountability for police departments as part of the ongoing campaign to end police violence in our communities,” the report concluded.