Last week a British man charged with the murder of his wife was found not guilty. Why? Because he strangled his wife, he says, in his sleep while dreaming that he was fighting off intruders. Three psychologists testified that he bore no responsibility for his actions, and the judge agreed.
This is the latest in a line of sleepwalking defense cases that have been adding up over the last 30 or so years. In 1982, an Arizona man was found not guilty after stabbing his wife 26 times, allegedly while sleepwalking.
In 1987, a Canadian man was found not guilty of murder after he bludgeoned his mother-in-law with a tire iron and stabbed her to death with a kitchen knife, allegedly while sleepwalking. He drove 14 miles to reach his in-laws’ house, also while sleeping–or so the defense argued and the court believed.
In 1994, a Pennsylvania man who shot his wife to death claimed that he was sleepwalking when he committed the crime and had no memory of the murder. In this case the jury didn’t buy the argument and sentenced the man to life in prison.
In 1997, an Arizona man stabbed his wife 44 times with a hunting knife. He then dragged her into a backyard pool and held her head under water. His defense: sleepwalking. The jury didn’t buy it in this case either.
In 2001, a California man on vacation with his girlfriend smashed her head with a flower pot and then stabbed her to death. He claimed that he was dreaming of fighting off an intruder. The jury gave him 26 years to life.
The defendant was diagnosed with a genuine sleep disorder in the most recent case, but whether a sleep disorder–even a severe disorder–explains murder is debatable at best.
An article in New Scientist reviews a selection of research attempting to identify whether people are in control of their actions while sleeping. Where this research leads may ultimately determine whether the sleepwalking defense passes muster with more juries or gets laughed out of court.
From the article:
Last month, Ursula Voss of Bonn University in Germany and colleagues reported that even during lucid dreaming– a state in which some people claim to be able to control their dreams – some areas of the brain associated with intent stayed offline, while other areas associated with consciousness were active. “As long as you are in a dream, you have no free rein on your actions and emotions,” says Voss (Sleep, vol 32, p 1191).
Although this research didn’t look specifically at sleepwalkers, it tallies with a previous study by Claudio Bassetti at the University of Zurich in Switzerland, who once managed to manoeuvre a sleepwalker into a brain scanner during a sleepwalking episode. He found the sleepwalker also showed no activation in the areas of the brain associated with intent, though emotional areas and those associated with movement were active (The Lancet, DOI: 10.1016/S0140-6736(00)02561-7).
Our judgement is off and our ability to act out emotionally is on,” says Rosalind Cartwright of the Sleep Disorder Service and Research Center in Chicago. She believes a confirmed diagnosis of sleepwalking would make a strong defence in court, but says better tests are needed to establish who has a genuine sleep disorder.