Multi-Method Evaluation of Police Use of Force Outcomes: Final Report to the National Institute of Justice

• NCJ Number: 231176
• Author(s): Michael R. Smith, J.D., Ph.D.; Robert J. Kaminski, Ph.D.; Geoffrey P. Alpert, Ph.D.; Lorie A. Fridell, Ph.D.; John MacDonald, Ph.D.; Bruce Kubu
• Date Published: January 2009
• Length: 173 pages
• Grant Number(s): 2005-IJ-CX-0056
• Agencies: NIJ-Sponsored
• Publication Type: Report (Study/Research)
• Award: A Multi-Method Evaluation of Police Use of Force Outcomes

Annotation

This exploratory study focused on the identification of factors related to injuries to police officers and citizens during use-of-force events.

Abstract

Findings show that the use of physical force and hands-on control increase the risk of injury to officers and citizens. Increasing levels of suspect resistance were associated with an increased risk of injury to both officers and suspects. Regarding the use of pepper spray by officers, the multiagency analysis indicated that its use reduced the probability of injury to suspects by 70 percent. For officers, the use of pepper spray increased the probability of injury by 21 to 39 percent. Regarding the use of conducted electrical devices (CEDs), they significantly reduced the probability of injuries, after controlling for other types of force and resistance. Aside from officer force and suspect resistance variables, few other factors correlated with injury outcomes. In the multiagency models, male suspects were twice as likely as females to be injured in a use-of-force event. The presence of a male suspect slightly increased the risk of injury to officers compared to female suspects. In Seattle, WA, where officer gender was available for inclusion in the models, female officers were more than twice as likely as male officers to be injured in use-of-force events. The study used a nationally representative survey of U.S. law enforcement agencies to provide an overview of how less-lethal force technologies, training, and policies are linked to use-of-force events. Data from three agencies were analyzed separately in order to identify individual and situational predictors of injuries to officers and citizens during use-of-force events. Use-of-force records from 12 police agencies were combined and analyzed, and a longitudinal analysis was conducted in order to determine the effect on injury rates of the adoption of the Taser by 2 police agencies. 28 tables, 3 figures, 5 references, and appended supplementary methodological information and data