After falling asleep on the couch, 23-year-old Kenneth Parks got up in the early morning hours, put on his shoes and jacket, and drove his car for 20 minutes, through traffic lights and down a winding road, to his in-laws’ home. He grabbed the tire iron from his car and a knife from the kitchen and proceeded to strangle his father-in-law to the point of unconsciousness. He then stabbed his mother-in-law to death. While he didn’t harm his in-laws’ teenage daughters, they reported that Parks was grunting like a wild animal. Parks later drove himself to a police station where he reported that he thought he had killed his mother-in-law because he had memories of her being in pain. The deep cuts and blood on his fingers provided evidence to support his story.

Although this appeared to be an open-and-shut case leading to a guilty verdict, after considering the testimony of sleep experts, the jury acquitted Mr. Parks of the murder of his mother-in-law and the attempted murder of his father-in-law. They found that he could not be held responsible for his actions that dreadful night.

Behind the Scenes

What led to the acquittal of Kenneth Parks? The jury determined that he was sleepwalking and sleep-attacking, with no conscious control over his actions. Surprising conclusion, isn’t it? Sleep violence has been self-reported in about 2% of the population, but such sleep responses rarely become murderous (Siclari et al., 2010; Siclari, Tononi & Bassetti, 2012). When the sleeping brain turns to violence, the behavior is considered an example of an automatism, an involuntary complex response that occurs outside of conscious awareness, not unlike the behavior of zombies appearing on movie and television screens (Moorcroft, 2003).

Sleep is considered an altered state of consciousness characterized by diminished awareness. Researchers investigate the biological basis of sleep primarily through electroencephalograms (EEGs), which reveal shifts in brain wave activity, several of which occur at various points throughout sleep. The different stages of sleep can be easily determined in sleep laboratories by measuring patients’ EEGs with electrodes. However, the jury obviously had no EEG recordings to determine if Parks was indeed asleep the night he murdered his mother-in-law. Such cases recruit the expertise of forensic psychiatrists who work within the legal system to determine criminal intent and psychological competency of defendants.

Sleep clinician Carlos Schenck, who worked as a consultant on this case, agrees with the jury’s decision. Schenck based his conclusion on the following factors: (1) Parks had both a personal and a family history of parasomnias (i.e., talking, walking, and eating during sleep, as reported by his family members); (2) he had been sleep deprived prior to the incident and had experienced significant physical stress playing rugby; (3) he had recently experienced significant emotional stress due to a gambling debt; (4) he had cut the tendons in his fingers yet reported experiencing no pain; and (5) he had organized a picnic at his in-laws’ home the next day, which suggested that driving to his in-laws was likely an event that he had mentally rehearsed the day of his mother-in-law’s death (Schenck, 2011).

Indeed, considering that past research has shown that men are more likely than women to behave violently when they have sleep disorders, Parks appeared to be a textbook case for sleep violence. This gender difference may exist because men are more susceptible than women are to excessive life stressors, disturbed sleep, and drug abuse (even though no drug abuse was reported in this case) (Siclari, Tononi & Bassetti, 2012).

No absolute truths exist in this case, just a convergence of evidence. Yet, this case raises many intriguing questions about the brain activity that underlies conscious awareness and about just what our brains and minds do after midnight.