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People with Mental Illness, 2nd Edition

Guide No.40 (2022)

by Gary Cordner, Michael S. Scott and Manuel J. Sanchez 

Police Interactions with People with Mental Illness

Problems associated with people with mental illness† pose a significant challenge for police.[1] This guide begins by describing the nature of police interactions with people with mental illness and reviewing factors that increase the challenges that police face in relation to the mentally ill. It then identifies a series of questions that might help you analyze your local policing problems associated with people with mental illness. Finally, it reviews responses to the problems and what we know about these from evaluative research and police practice.

† Recently, the term “behavioral health” has been substituted for the term “mental illness” to draw greater attention to people’s actions rather than to their state of mind and to try to further destigmatize these conditions and to acknowledge that many people with mental disorders manage them well enough that they do not negatively affect their behavior.

Police officers frequently encounter people with mental illness—estimates of the proportion of U.S. residents with a mental illness range from 5 to 25 percent.‡, [2] Similar estimates are found in Canada, Australia and the United Kingdom.[3] About one-quarter of college students report being treated for a mental disorder, making the issue as important for campus police as it is for municipal and county police.[4] Numerous studies confirm that police officers in many jurisdictions commonly have encounters with mentally ill people. Between 1 and 20 percent of all calls for police service involve people with mental illness, and, for people with mental illness, roughly one-quarter have been arrested by the police.[5], § 

‡ Estimates vary in terms of what forms of mental illness are included, as well as over time as diagnostic definitions and practices change. Unfortunately, there is no standard definition of mental illness. Medical doctors, research scientists, psychiatrists, psychologists, and social workers define it differently, depending on whether their focus is on organic conditions, personality, or behavior. One working definition designed for policy makers is “Mental illness is a biopsychosocial brain disorder characterized by dysfunctional thoughts, feelings, and/or behaviors that meet DSM-IV diagnostic criteria” (Kelly, 2002). The same report identifies the main examples of serious mental illness as:

  • All cases of schizophrenia (a psychotic disorder)

  • Severe cases of major depression and bipolar disorder (mood disorders)

  • Severe cases of panic disorder, obsessive-compulsive disorder, and post-traumatic stress disorder (anxiety disorders)

  • Severe cases of attention deficit/hyperactivity disorder (typically, a childhood disorder)

  • Severe cases of anorexia nervosa (an eating disorder).

§ These estimates likely vary considerably across jurisdictions and neighborhoods, both because people with mental illness are more likely to reside close to needed mental health treatment resources and because of the variability in how police classify calls for service involving mental illness.

A person’s mental disorder is not always apparent nor relevant to the situation at hand: many people experience lower-level mental disorders that do not manifest themselves as behavioral concerns calling for special treatment by police. However, where police initiate emergency mental-health detentions, the diagnosed mental disorders tend to be more severe and challenging to treat than is the case when police are not making the referral.[6] 

Mental illness is not, in and of itself, a police problem. Obviously, it is a medical and social services problem. However, a number of the problems caused by or associated with people with mental illness often become police problems. Whether the behavior or condition of the mentally ill person is best handled by police, mental-health professionals, social workers, or someone else, the police play a critical role in determining how best to help the person. Some mentally ill people might not otherwise get connected to the services they need were it not for police intervention.[7] 

Common Situations 

Police officers encounter people with mental illness in many types of situations, and in roles that include criminal offenders, disorderly persons, missing persons, complainants, victims, and persons in need of care (see Table 1.). 

Table 1. Roles of People with Mental Illness and Examples




·   A person with mental illness commits a crime

·   A person with mental illness threatens to injure someone else in the delusional belief that that person poses a threat to him or her

·   A person with mental illness threatens to injure police as a means of forcing police to kill him (commonly called “suicide by cop”)

Disorderly person

·   A family or community member reports annoying or disruptive behavior by a person with mental illness

·   A hospital, group home, or mental health facility calls for police assistance in controlling a person with mental illness

·   A police officer on patrol encounters a person with mental illness behaving in a disorderly manner

Missing person

·   A family member reports that a person with mental illness is missing

·   A group home or mental health institution reports that a person with mental illness walked away and/or is missing


·   A person with mental illness calls the police to report real or imagined conditions or phenomena

·   A person with mental illness calls the police to complain about care received from family members or caretakers


·   A person with mental illness is the victim of a crime

·   A family member, caretaker, or service provider neglects or abuses a person with mental illness

Person in need of care

·   A person with mental illness threatens to commit suicide

·   Police are asked to transport a person with mental illness to or from a hospital or mental health facility

·   Police encounter a person with mental illness who is neglecting his or her own basic needs (food, clothing, shelter, medication, etc.)


A common perception is that people with mental illness are disproportionately involved in violent crime. People with mental illness have comparable rates of and reasons for committing violent acts as offenders without a mental illness.[8] Drug and alcohol abuse, and noncompliance with medication requirements can contribute to violent behavior.[9] In general, however, most persons with mental illness are not criminals, and of those who are, most are not violent[10] even though for some crime types—for example, some types of arson, sexual assault and murder––a substantial percentage of offenders have some mental disorder.[11] In sum, the relation between mental illness and crime is more complex than many people imagine it to be.

Police interactions with people with mental illness can be dangerous, but usually are not. In the United States, 2,358 of the 60,105 (about 4%) police officers assaulted in 2020, and 7 of 503 (about 1.4 %) police officers feloniously killed from 2011 to 2020 were killed during an encounter with an emotionally disturbed person.[12] These represent relatively small portions of all officers assaulted and killed. 

People with severe mental illness are more likely than people without a mental illness to be killed by police.[13] Although police are somewhat more likely to use force against people with mental illness, this is largely due to mentally ill persons being somewhat more likely to physically resist police officers, but that does not necessarily lead to greater injuries to either the officer or the person with mental illness.[14] Some, but not all, studies also find that people with mental illness are more likely to be under the influence of drugs or alcohol, which can also increase the likelihood that police force will be used. Whether police officers unreasonably fear people with mental illness and thereby use greater force than necessary or people with mental illness act in ways that give police officers reasonable fear for their own safety remains much debated, and not definitively settled by research. 


The harms associated with the police handling of people with mental illness are implicit in the situations and examples the table provides, but deserve some discussion. A person with mental illness may harm other citizens by committing personal or property crimes or engaging in disorderly and disruptive behavior. Alternatively, a person with mental illness may be harmed as a crime victim, as an abused family member or patient, as a person who suffers through self-neglect, or as a person whose mental health problem has left him or her erroneously subjected to criminal charges and jail confinement. People with severe mental illness are much more likely to be the victim of a crime than the general public, partly due to their mental impairments and partly due to social factors such as poverty, homelessness, social isolation, involvement in criminal activity, and substance abuse.[15] Society in general may be harmed if excessive police, criminal justice, and/or medical resources are consumed by problems associated with people with mental illness. Inadequate or inaccessible mental health treatment, or inefficient processing of people with mental illness in either the criminal justice or mental health systems account for much of this financial harm to society, as well as to the people with mental illness.[16] 

It is important to keep the concept of harm in mind when addressing this particular problem, because there is a tendency to simply define people with mental illness as the problem, and getting them out of sight as the solution. In contrast to most police problems, however, this is not one that involves wholly voluntary behavior— rather, it involves behavior that medical conditions cause or compound. Consequently, police have to be careful not to blame people with mental illness, but instead focus on behavior that causes harm to self or others. 

Related Problems 

The police problem of people with mental illness is closely connected to three other problems noted below. This guide does not specifically address these problems, but addressing people with mental illness in your jurisdiction may require that you take on these problems, as well: 

·         homelessness†

 See Problem-Specific Guide No. 56, Homeless Encampments, for further information.

·         drug abuse

 See Problem-Specific Guide No. 24, Prescription Drug Fraud and Misuse, 2nd Edition, for further information.

·         alcohol abuse

 See Problem-Specific Guide No. 68, Chronic Public Inebriation, for further information.

Many of the people who suffer from mental illness and have contact with the police are also frequently homeless[17] and that being homeless and severely mentally ill greatly increases the likelihood of being arrested.[18] 

The co-occurrence of mental illness and being under the influence of a substance can be challenging for police officers. As stated earlier, people with mental illness who are also under the influence of drugs or alcohol can increase the likelihood of suspect or officer injury. The likelihood of an officer encountering someone who is both mentally ill and under the influence can be high.[19] 

Factors Contributing to the Problem 

Understanding the factors that contribute to your problem will help you frame your own local analysis questions, determine good effectiveness measures, recognize key intervention points, and select appropriate responses. Four principal factors that strongly affect the current mental health situation in America are deinstitutionalization, criminalization, medicalization, and the availability of mental health treatment resources. 


Perhaps the single biggest factor affecting the policing of people with mental illness has been deinstitutionalization.[20] During the 20th century, and especially after 1960, public attitudes, laws, and professional mental-health practices changed, leading to the closing of many state hospitals, psychiatric hospitals, and what used to be called insane asylums. Society’s preference, as well as legal rulings, shifted away from institutionalizing people with mental illness.[21] This was largely a positive development that resulted in more humane and effective treatment for people with mental illness. Unfortunately, the community-based services intended to replace institutional treatment were inadequate to the need in many communities. The gaps left by deinstitutionalization has resulted in society’s relying heavily on police as one of the primary gateways for people with mental illnesses to receive treatment. 


Predictably, calls to the police about crimes and disorder involving people with mental illness increased in the wake of deinstitutionalization, including rising homelessness among that population.[22] Police sometimes try to handle many of these calls informally, particularly when options are limited. Frequently, efforts at civil commitment are unsuccessful (the person has to pose a danger to him- or herself or others, in addition to being deemed mentally ill), and other inpatient or outpatient mental health services are often unavailable, cumbersome, or uncooperative.[23] Inevitably, police have often turned to arrest and a trip to jail as the only available solution to the immediate problem. This has had the general effect of criminalizing mental illness and reinstitutionalizing people with mental illness—but in jail or prison instead of a psychiatric facility. Around 14.5% of males and 31% of females entering jail have some form of mental illness.[24] 

The criminalization of mental illness could reflect either a shifting preference for punishing the behavior of mentally ill people or a reluctant conclusion by police that arrest is the more viable means of providing them mental-health care. How police officers choose to handle incidents involving persons with mental illness depends on a combination of factors, including available alternatives to arrest, the degree to which their agency affords them discretion in choosing among alternatives, the practicality of each response option, and their comfort level with making this complex judgment.[25] 


The dominant treatment for mental illness has evolved from electric shock and psychotherapy more toward medication. To be sure, other treatments remain viable, and combined treatments are generally preferred, but today, medication plays a vital role. Consequently, an important aspect of community-based mental health care is getting noninstitutionalized people with mental illness to take their medication as prescribed.[26] Factors that interfere with regular use of prescribed medications include the negative side effects associated with some drugs, the high cost of medication, the tendency to self-medicate, the abuse of illegal drugs and alcohol, and the lack of monitoring/follow-up by the overtaxed community-based mental health system. It can take time and repeated experimentation to find a psychiatric medication regime that works well for an individual such that they are likely to adhere to their treatment.[27] Recent advances in psychiatric treatments—such as cognitive behavioral therapy[28] and controlled use of psychedelics[29]—hold significant promise for controlling some of the mental disorders that are commonly contributing to police involvement. 

Availability of Mental Health Treatment Resources

The number of contacts police have with mentally ill persons, and the nature of those contacts, are heavily influenced by the overall availability of mental health treatment resources in that community. Where mental health treatment is readily available, fewer people are likely to engage in the sort of behavior that leads to police being summoned. Untreated mild forms of mental disorders can worsen progressively to the point that dangerous or bizarre behaviors are more likely to occur, and police, in turn, to be called. It is generally the case that mental health treatment is less available in both rural and highly urbanized, impoverished communities.[30] In jurisdictions where a trip to transport a person to a mental-health facility and/or the waiting time in a mental health facility can take several hours, that option might leave the jurisdiction without much of its police coverage for an entire police shift.[31] Moreover, as bed space in psychiatric hospitals becomes scarcer, police often wind up taking people in mental crises to regular hospital emergency rooms where they are then admitted to regular hospital rooms until space in a psychiatric facility becomes available. This increases the likelihood that police will be called to regular hospitals to help control some of these patients.[32]

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