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Police Use of Force and People with Mental Illness

Police Use of Force and People with Mental Illness

University of Massachusetts

Synopsis: A retrospective study of data from the Portland Police Bureau dispels the idea that use of force encounters with people with Mental Illness are significantly more dangerous to the parties involved in the incident.


Community Need

Police consider interactions with people with mental illnesses to be extremely dangerous. This has largely been based on the perceptions of law enforcement officers themselves. Yet, existing empirical evidence does not support this perception. Data indicate that few, if any, injuries to police officers result from encounters with people with mental illnesses. A conflicting viewpoint has emerged that people with mental illnesses are more likely to be injured in encounters with the police.


To address this limited knowledge and to understand more clearly the outcomes of police interactions with people with mental illnesses, this study examines use-of-force reports collected by the Portland Police Bureau between 2008 and 2011 to determine whether encounters with people with mental illnesses are more likely to result in injury to officers or subjects when force is used.


Primary Research Question(S)

What is the likelihood of injury for either police or the subjects during encounters when force is used by the police?

Research Design

This study examined all use-of-force cases recorded by the Portland Police Bureau from 2008 to 2011. Whenever an officer uses force, an officer is injured, or a subject is injured, officers are required to complete a use-of-force form and the case is recorded as such. The researchers identified dependent and independent variables. From the data, they examined the likelihood and correlates of injury for both police and subjects during use-of-force encounters. The researchers specifically isolated the effects of mental illness on the likelihood of injury. To address the research questions, they employed two multivariate logistic regression models predicting (a) any officer injury and (b) any subject injury. The use-of-force documentation included details about the encounter, including the precinct, event conditions, subject behavior, and officer actions.


The research depends on the veracity and comprehensiveness of the use-of-force reports. The researchers do not know whether officers are filling out the forms properly. The data also does not include officer characteristics such as race, education, and years in service. The researchers also could not tease out the role that Crisis Intervention Team (CIT) training had on the results (PPB was trained in CIT during the years examined). The data also does not take into account any prior encounters between the police and the subjects, and evidence suggests that a familiarity with the people with mental illnesses may result in fewer injuries. Finally, the sample includes only use-of-force incidents and not all police contacts.


Research Findings

The findings are consistent with the large body of literature examining the use of force: injury to a subject and/or injury to an officer are most likely when subjects are armed, resist police commands, assault an officer, or are involved in a foot chase. Mental illness alone is not predictive of injury for either police officers or subjects. The findings also show that when mental illness is co-occurring with substance use, the likelihood of injuries for both officers and subjects increases significantly. This is true for subjects without mental illness but who are under the influence of drugs or alcohol.

Main Implications

If incidents involving people with mental illness are not significantly more likely to end in injury to either the officer or the subject, then the perception of dangerousness is overstated and may result in unnecessary stigmatization of this population. Policies should be implemented that help to reduce the stigma attached to mental illness among police officers. Training for police should be expanded to include tools to identify mental illness across a larger range of calls for service.


Morabito, M. S., & Socia, K. M. (2015). Is dangerousness a myth? Injuries and police encounters with people with mental illnesses. Criminology & Public Policy, 14(2), 253-276.