Violent behaviors during sleep may result in events which have forensic science implications. The apparent suicide (for example, leap to death from a second-storey window), assault or murder (for example, molestation, strangulation, stabbing, shooting) may be the unintentional, non-culpable but catastrophic result of disorders of arousal, sleep-related seizures, REM sleep behavior disorder (RBD), or psychogenic dissociative states. Violent sleep-related behaviors have been reviewed in the context of automatic behavior in general, with many well-documented cases resulting from a wide variety of disorders. Conditions associated with sleep-period-related violence fall into two major categories: neurologic and psychiatric. Psychogenic dissociative disorders may arise exclusively or predominantly from the sleep period. Recent interest in the forensic aspects of parasomnias provides sleep medicine professionals with an opportunity to educate and assist the legal profession in cases of sleep-related violence. One infrequently used tactic to improve scientific testimony is to use a court-appointed impartial expert.