The police were called because a man had been badly beaten in his own home and needed to be rushed to the hospital. When they arrived the man was barely conscious, had multiple head wounds and was bleeding profusely. The ambulance was already on the way. His wife was in a state of shock but had the presence of mind to call 911 when she realized that the attack had occurred. Strangely, she had serious arm and hand wounds but could not recall having fought off the attacker. She was somewhat confused and seemed drowsy despite the serious crime that had just occurred. There was no evidence of forced entry into the house and the alarm system was on and apparently functioning correctly. A home intrusion had not been detected. The police were struck by the wife's mental state and noted an open bottle of a well-known sleep medication on the couple's nightstand. They were uncertain as to how the attack could have occurred. They attempted to question the husband while he was on a stretcher, prior to being taken to the ER. He was coherent but could only remember vaguely having been deeply asleep when he gradually became aware that he was being pummeled.
While not the most common scenario for a crime scene investigation, these kinds of events are being reported. After a thorough review of the evidence it became apparent that the husband was attacked by his wife. It looked like a case of domestic violence. But why would she do this? Were there marital problems? Apparently not. She seemed completely confused at the time of the investigation but did not deny the allegations. She just could not figure out how she could have attacked her husband and was disturbed by her own serious arm and hand injuries. In fact many of the bones in her right hand were broken. The police decided against charging her because they determined that this was a sleep-related attack without consciousness or premeditation. In cases such as this, appropriate questioning of the apparent perpetrator is vital. When sleep related behaviors are involved, the subject is often dazed and confused and makes no effort to deny the allegations and usually expresses pained bafflement about how they could have done such a thing.
A new area of sleep medicine has recently developed to deal with legal issues related to sleep. It may be difficult to imagine that the field of forensic sleep medicine could actually exist. How can crimes be associated with sleep? It is well know that complex behaviors can occur while people are asleep and that these can sometimes be very violent. People may injure themselves, sometimes seriously, and can also lash out at others including perpetrating sexual assaults. Indeed, sleep disorder defenses have been successfully used in serious cases including rape.
In the above case, a number of possible sleep disorders could be involved. For example, her sleep may have been disturbed by sleep disordered breathing (sleep apnea) resulting in acting out a violent dream. Alternatively, she may be developing REM Sleep Behavior Disorder that also results in the acting out of often-violent dreams. It is even possible her sleep behaviors could have resulted from the effects of her sleeping medication. I have encountered clinical situations in which patients have taken additional doses of sleeping medication while somnambulating, further exacerbating the sleep walking. (You may have noted the warnings about dangerous behaviors that are now given on advertisements for certain well known sleeping medications.)
From time to time in future blogs I will be discussing forensic sleep cases that I am directly familiar with or that have been reported in the media. Not all crimes occur during waking hours...
