The Washington Post
2015
https://www.washingtonpost.com/graphics/national/police-shootings/
2016
https://www.washingtonpost.com/graphics/national/police-shootings-2016/
2017
https://www.washingtonpost.com/graphics/national/police-shootings-2017/
People have been shot and killed by police; this database is based on news reports, public records, social media and other sources. It provides a methods section on how numbers are collected.