An empirical analysis of over 300 UD reports from 11 law enforcement agencies (10 U.S. agencies, 1 non-U.S. agency), dated between 1974 and 2016, was performed to determine the implications of such data for firearms training. The data involved a wide variety of manufacturers, models, trigger mechanisms, and trigger weights. All agencies provided approval for the confidential analysis and publication of the data contained in the reports