Sleepwalking disorder and mens rea: a review and case report. Maricopa County Superior Court.

This paper examines complications of sleepwalking disorder (DSM-IV 307.46), an arousal disorder or parasomnia, in relationship to mens rea, or culpable mental state necessary to a finding of criminal responsibility. The legal history of criminal intent and insanity is reviewed. A case of indecent exposure is discussed in a man with a history of closed head injuries and sleepwalking disorder who was found standing naked in the middle of a busy urban thoroughfare in the wee hours of the morning and arrested. On psychiatric evaluation, the defendant was found to have a long-standing sleepwalking disorder. At trial, scientific literature and psychiatric expert testimony concerning sleepwalking disorder was presented. The psychiatrist opined that the defendant was probably sleepwalking at the time of the alleged offense. No rebuttal testimony was offered by the prosecution. The jury found the man not guilty. The author surveys the legal history of sleepwalking disorder and compares this example with others in which uncontrolled behavior during sleep has resulted in harm to the patient or to others. Clinical and forensic implications of the disorder are reviewed. The parasomnias' impact on forensic practice should be systematically studied. Intervention strategies should be refined and implemented.