American history is littered with cases of sleepwalking killers – usually men who wake in the night and kill their wife or lover. The best-known historical case is that of Albert Tirrell, who, in 1845, killed his lover, Maria Bickford. They had been having an affair, and after being repeatedly caught by his wife’s family, he decided to kill Bickford and set fire to the building they were sleeping in – apparently to conceal the evidence of his crime. Unfortunately, the landlord was awoken by Bickford’s screams, and Tirrell was eventually caught and tried. He was acquitted of arson and murder, but found guilty of adultery. The rationale – provided by his use of the defense that he was asleep when he committed the murder and started the fire – was that he didn’t choose to kill Bickford, although he had chosen to continue his affair with her.
The use of the sleepwalking defense returns from time to time – which I discuss in The Slumbering Masses. The most tragic case – from the 1870s – is that of Simon Fraser, who, disoriented upon awakening from a nightmare, dashed his son against the floor of the room he and his wife shared with the toddler. He was acquitted for the murder, since it was so clear to the jury that he had no desire to kill his child. In the 1980s, Steven Steinberg killed his wife Elena, and Scott Falater used the same defense in the 1990s for the death of his wife Yamila – both in Arizona. But Kenneth Parks’ case – in which he killed his mother-in-law in Toronto (and captured in the Lifetime film, The Sleepwalker Killing, starting a young Hillary Swank) – was a real proving ground for the sleepwalking defense and the science of sleep.
In an incredible but not unheard of case of sleepwalking behaviors, Parks drove the twenty-three kilometers between his home and that of his in-laws, ascended their stairs, and attacked his mother-in-law with a bludgeoning instrument and then a kitchen knife, stabbing her to death. He then choked his father-in-law into unconsciousness after his father-in-law awoke and attempted to stop Parks. Parks roamed the house briefly afterwards, attested to by the teenaged children of his parents-in-law who still lived in the home – who reported hearing his “animals noises.” Parks then left the home and awoke at some point during his drive back home. He then redirected himself to a nearby police station and presented himself to the officer on duty at the station’s front desk, bloodied and wounded – he had lacerated both of his hands during the stabbing of his mother-in-law, a point that would prove critical in his successful defense.
Parks had been recently fired due to the embezzlement of funds from his employers in an attempt to pay off debts related to an escalating gambling debt. He had had bouts of gambling previously, but it was a windfall of a payoff that led to an escalating interest in horse racing, which quickly ended with him in debt. He had confessed his financial problems to his wife, and on the night of the murder – a day before he and his wife were to tell his parents-in-law of their financial situation – he fell asleep in front of the television while watching an episode of Saturday Night Live. By all accounts, Parks was under a great deal of stress, depressed, and suffering from insomnia; he also had a history of parasomnia behaviors including sleepwalking, enuresis, and night terrors. All of these factors – his remorse and confusion about the attacks, his self-inflicted wounds, his family and personal history, and the mitigated factors of his social life – combined to make sense of his sleepwalking behaviors.
Since Parks’ trial in the late 1980s, the science of sleep has undergone a number of changes in how sleep is thought about – and sleepwalking is one of the behaviors that has led to these revisions. Once thought of as a global phenomenon – meaning that our whole brain is either asleep or awake – now scientists are coming to understand that sleep is a local phenomenon. Parts of the brain may be asleep while others are awake, and only when most of our brain is asleep do we actually sleep. But if parts of our brain awake while we sleep, we might undergo parasomnia behaviors – sleepwalking, sleep eating, sexsomnia, or something more complex, like sleep driving.
When someone is sleep-deprived, under stress, and has a history of sleepwalking, they’re more likely to experience parasomnia behaviors. If he or she has also been drinking alcohol or using drugs (both prescription and recreational), things only become more complex. In Parks’ case, it was clear that he had no ill will towards his in-laws, and his personal circumstances and history helped to explain why he was such a restless sleeper that night. In other cases, it’s much less clear. And as scientists come to understand that pharmaceuticals that induce sleep (like Ambien, Lunesta and Sonata) can lead to people experiencing parasomnias, things become even more complex.
As the science of sleep continues to unraveling the complex biological and social forces that make up our daily sleep and wakefulness, it may be increasingly difficult to explain away any behaviors as strictly biological in origin. Legal systems might need to take science more seriously – beyond fMRIs and DNA analysis – and find scientists who can help explain the biological and social bases of our nighttime behaviors. Sleepwalking murders are extreme cases, but in coming to understand why sleepwalkers sometimes kill, we can also come to understand everyday parasomnias like sleepwalking and sleep eating and the disruptions they cause for individuals and families. And when we come to understand that it isn’t just biology causing people to wake up in the middle of the night and eat peanut butter by the handful or harm their loved ones, we can come to help treat the causes of disorderly sleep and not just its symptoms.