Study Findings: Factors Affecting Injuries

Sidebar to the article Police Use of Force: The Impact of Less-Lethal Weapons and Tactics by Philip Bulman

Physical Force

Physical force and hands-on control increased the risk of injury to officers and citizens. When controlling for the use of CEDs and pepper spray in the multiagency analysis, using force increased the odds of injury to officers by more than 300 percent, and by more than 50 percent to suspects.

close-up of cuffed hands

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Suspect Resistance

Increasing levels of suspect resistance were associated with an increased risk of injury to officers and suspects. The increased injury risk was especially acute for officers. These findings suggest that officers, rather than suspects, face the most increased injury risk when suspects resist more vigorously.

Pepper Spray

The overall analysis (of 12 agencies) showed that pepper spray use reduced the likelihood of injury to suspects. For officers, however, pepper spray use increased the likelihood of injury. This finding was unexpected, and further research may help to explain how officers choose to use pepper spray instead of CEDs.


Except for Richland County, where its effects were insignificant, CED use substantially decreased the likelihood of suspect injury. The analysis of 12 agencies and more than 24,000 use-of-force cases showed that the odds of suspect injury decreased when a CED was used. CED adoption by the Orlando and Austin police departments reduced injuries to suspects and officers over time.

Demographic Characteristics

The 12-agency analysis showed that male suspects were twice as likely to be injured as female suspects. In that analysis, the presence of a male suspect slightly increased injury risk to officers. In Seattle, female officers were more than twice as likely to be injured as male officers. In Miami-Dade and Seattle, where suspect race was available as a variable for analysis, the odds of injury for non-white suspects were lower than they were for white suspects.

Date Created: March 3, 2011