Mentally Ill Offenders

Crime and Mental Illness

Direct measures of the relationship between crime and mental illness are unavailable, because much crime and mental illness go undetected. The most authoritative [Page 1047]information comes from two types of studies: (1) psychological screening of jail and prison inmates and (2) interviews with the general population. The results of these studies reveal that although people who suffer from serious mental illness are more likely to be arrested than members of the general public, the offenses for which they are arrested are similar to those resulting in arrest among the general public. Mentally ill, homeless people who also use alcohol and illegal drugs are particularly likely to be arrested because their functioning may be severely impaired and they may engage in bizarre or threatening public behavior. About half the people who are homeless are also mentally ill.

Large-scale community surveys, in which people report their own experience with both mental illness and violence, find that people with mental disorders are more violent than people without such disorders. The most violent mentally ill people are lower class, young males. People recently discharged from mental hospitals are likely to be more violent than the general population.

Judicial Processing

When the perpetrator of a serious assault is identified, the police arrest the suspect, regardless of the suspect's mental health status. When the offense is minor and the suspect is mentally ill, the police exercise their discretion to either make an arrest or refer the suspect for mental health treatment. Most jails routinely screen all newly admitted defendants for mental illness to reduce the risk of suicide, assault, and victimization, but typically, only larger jails have counseling, therapy, or special housing for inmates identified as mentally ill.

Defendants charged with crimes may claim they are incompetent to stand trial (IST), an assertion that they are unable to understand the charges against them nor assist in their own defense. Defendants found IST may be committed temporarily to a mental health facility. Criminal charges are dropped for defendants remaining incompetent, although civil commitment proceedings may be instituted when defendants meet the legal standard for involuntary commitment. Defendants who recover sufficiently during temporary commitment may be tried on the original charges. Although national statistics are not routinely collected on the judicial processing of mentally ill offenders, several research studies provide good estimates of the national pattern. About 25,000 people were evaluated for competency to stand trial in the United States in 1978. About 6,000 of these (25 percent) were found incompetent. Criminal defendants found IST are hospitalized for about as long as convicted defendants are incarcerated in jail or prison. Defendants found IST on minor misdemeanor charges are frequently hospitalized longer than defendants convicted and jailed on similar charges.

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