Police Violence

Violence committed by police officers in the United States is paradoxically highly documented and incompletely documented. We frequently encounter this situation in our work—some victims’ stories are told by many sources, while other victims’ stories are rarely if ever told. This is the gap statistics can fill. 

In 2015, the US Bureau of Justice Statistics concluded that two federal efforts to document deaths that occur during arrest were woefully incomplete. Their analysis relied on the same statistical methods HRDAG’s team has been using internationally for decades, so we examined their approach, considering various assumptions required by the method. This work resulted in an essay in Granta magazine, Violence in Blue,” written by our director of research Patrick Ball, which concluded that one-third of all Americans killed by strangers are killed by police. Following the murder of George Floyd by Minneapolis police officers on May, 2020, Patrick refreshed the article with a new introduction, writing, “This cannot be acceptable in democracy.”

Most recently we have been working with our partners at the Invisible Institute’s Citizens Police Data Project to design and maintain a data pipeline, to systematically process large quantities of documents describing potential police misconduct in Chicago.

Key publications on police violence:

Patrick Ball (2020). Refresh of Violence in Blue (Granta, March 2016) with new introduction. 8 June, 2020. © 2020 Granta.

Kristian Lum and Patrick Ball (2015). Estimating Undocumented Homicides with Two Lists and List Dependence. HRDAG, April 2015.

Kristian Lum and Patrick Ball (2015). How many police homicides in the US? A reconsideration. HRDAG, April 2015.

Kristian Lum and Patrick Ball (2015). BJS Report on Arrest-Related Deaths: True Number Likely Much Greater. HRDAG, March 2015.

photo by Flickr user John Liu, CC-BY-2.0, modified by David Peters


Our work has been used by truth commissions, international criminal tribunals, and non-governmental human rights organizations. We have worked with partners on projects on five continents.

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