Crime Library: Criminal Minds and Methods

Automatism: The Sleepwalker's Defense

Brain Waves and Criminal Behavior

Polysomnographic record
Polysomnographic record

Researchers at sleep disorder institutes around the world study the brain waves of people experiencing night-time behavioral problems. They typically rely on a tool called a polysomnograph for neurological readings. The sleepwalking disturbance occurs as the brain is waking up but is not yet fully there. The person is emerging from REM sleep. The eyes are open, but, as a character in Macbeth states about Lady Macbeth's nocturnal wandering, "their sense is shut." In an institute in England, researchers have seen sleepwalkers ride a horse, cook a meal, repair machines, and carry on the semblance of a conversation. They might even eat their pet's food from the bowl. One man reportedly ate his own watch while asleep. Sleepwalking conventions can expose a hotel to considerable damage, not to mention bizarre behavior in front of other guests.

Lady MacBeth sleepwalking
Lady MacBeth sleepwalking

Stryker states that a defense of sleepwalking has been raised in about thirty murder trials around the world. He cites one case in which a detective committed the murder, and, when he investigated the crime initially unaware of his involvement, he himself saw where the evidence pointed.

The defense of automatism contends that the defendant was in at most a semiconscious mental state and thus could not have been consciously aware of the act committed. The same is said of someone who may have sustained a blow to the head or who acted after a seizure. In all such cases, if such lack of full consciousness is proven, criminal responsibility cannot be attached.

The law of automatism is well developed in Britain, often being linked to a disease or defect, which transfers the case to mens rea considerations, but such cases are rare in the U.S. Even those defendants who could use it tend to rely instead on a defense of insanity or diminished capacity. It's not easy to get juries to believe that someone could involuntarily commit murder while sleep-walking.

Ron Voegtli acted out his nightmares on a regular basis, subjecting his wife to abuse for thirty years. During the day, she said for ABC News, he was a wonderful man, but during the night there was no restraint on his behavior. An hour after going to bed, he would jump out and begin yelling and running around. He might grab a knife or other weapon as a means of protection. A few times he came into the bedroom and hit his wife, and once he grabbed her and tried to strangle her. Finally, he was treated with anti-convulsant drugs, which helped alleviate the symptoms. Otherwise, his case might have ended more like those below.


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