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Examining the Impact of External Influences on Police Use of Deadly Force Over Time

NCJ Number
Evaluation Review: A Journal of Social Research Volume: 27 Issue: 1 Dated: February 2003 Pages: 50-78
Michael D. White
Date Published
February 2003
29 pages
Using data from Philadelphia, PA for over 20 years, this study used interrupted time-series analysis (ARIMA) in order to examine the impact of legislation and judicial intervention on police use of deadly force, and it considered the impact of larger, community-level characteristics on levels of police use of deadly force.
Over the entire study period, annual rates of police shootings were not apparently linked to several key environmental influences, including population level, arrests for violent offenses, and homicide. Police shootings were only slightly linked to the rate of sworn police personnel. During the late 1980s, however, rates of violent-felony arrests, homicide, and police shootings all increased together. The analysis found that the legislative changes designed to control police shootings had no significant impact on levels of police use of deadly force. These findings support prior research that showed State law did not control police decisions to use deadly force. Regarding judicial injunctive intervention, little or no effects were found on levels of police use of deadly force. Apparently, efforts to restrain police use of deadly force through legislation and court action fail to overcome the influence of the internal police environment in shaping police practices in the field. There is evidence that danger factors in the police working environment, such as an increase in the rate of violent crimes, increases the likelihood that police will respond to perceived danger with deadly force. The study examined 982 police shootings in Philadelphia from 1970 through 1992. Data consisted of police reports and investigations of all police shootings that resulted in injury or death from 1970 to 1978 and from 1987 to 1992. Archives of The Philadelphia Inquirer were used to determine monthly deadly force totals during those years. 2 tables, 4 figures, and 25 references