Habitual offenders who are sociopaths are not commonly suicidal except for manipulative purposes, but a first-time offender may undergo a sense of hopelessness that precipitates a suicide attempt. Those likely to commit suicide in jail are minority males charged with a major felony involving aggression, aged 21-35, and unmarried. Suicide methods in jail include hanging by using bedsheets or clothing, setting oneself on fire, or drowning oneself in the toilet bowl. Types of suicidal behavior include intentional suicide because of physical or psychological pain, attempted suicide to obtain sympathy, unconscious self-destructive and dangerous behavior, death resulting from miscalculation in attempts to achieve autoerotic experiences by reducing oxygen supply, and physical mutilation rooted in aggression toward self. The first line of defense against jail suicide is the identification upon admission of persons at high-risk of suicide and the elimination of jail conditions that reinforce suicidal tendencies. Such procedures must be based on a thorough knowledge of the kinds of persons and conditions associated with suicide. The second line of defense consists of a trained staff prepared to notice behavioral signs that indicate possible suicidal tendencies. Counseling and drug treatment should be available for those inmates displaying suicidal behavior.