The mentally ill in the community -- often without supervision or active treatment and frequently living in disadvantaged, high-crime neighborhoods -- inevitably encounter police officers. They are likely to be arrested for minor offenses rather than receive a warning, because the police perceive their behavior as unpredictable. Most defendants who have mental disorders are not found legally "mentally ill" to the extent that they are found incompetent to stand trial, guilty by reason of insanity, or guilty but insane. Persons not legally "mentally ill" are labeled simply "criminals." They are likely to be incarcerated, where they receive minimal mental health services. Upon release, there is generally insufficient cooperation between the criminal justice and mental health systems in meeting the physical and emotional needs of mentally ill ex-offenders. 32 references.