In 1969, the Firearms and Tactics Section of the New York City Police Department instituted a procedure for the in-depth documentation and study of Police combat situations. It was designated Department Order SOP 9 (s. 69).

Data gathering began in January 1970, and over 6000 cases were studied during the 1970s. The study results and findings were released in 1981. The following sets out many of those that focus on shooting situations and shooting techniques.