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Warning: This post contains discussion of murder.
Have you ever sleepwalked? It can be disconcerting to realize that you did something even though you were fast asleep. But you probably haven’t been as upset as Kenneth Parks, who woke up to discover that he had committed murder.
On an early morning in May 1987 in Ontario, Canada, Parks drove several miles to his in-laws’ house, opened the door, bludgeoned his mother-in-law to death and tried to suffocate his father-in-law – all while he was asleep. Upon waking up from this sleepwalking episode, Parks immediately turned himself into the police. (The victims’ names were not made public.)
Somnambulism is the fancy word for sleepwalking, derived from the Latin words somnus (“sleep”) and ambulare (“to walk”). It is classified as a type of parasomnia and primarily affects children (DynaMed). There are a number of potential causes including stress, sleep deprivation, alcohol use, and thyrotoxicosis (DynaMed). In one survey, 25% of adult sleepwalkers reported concurrent anxiety or mood issues (Zadra et al., 2013). A number of studies have reported that high levels of sleep deprivation can increase sleepwalking events by a factor of anywhere from 2.5 to 5 (Zadra et al., 2013). Sleepwalking can occur at any point in the sleep cycle, but most often happens during non-REM sleep (DynaMed). While sleepwalking, the person’s eyes are typically open and they appear awake. They can engage in normal-seeming behavior, but their movements may be awkward. More complex behaviors – for example, driving a car, as Parks did – is more common in sleepwalking adults than children (Zadra et al., 2013). The sleepwalker will have no memory of the events that occurred while they were sleepwalking.
Violence during somnambulism is usually reactive, occurring when the sleepwalker is confronted by another person. The sleepwalker will not recognize the person they are attacking “even if it is a very close family member,” thinking instead that the person is some sort of intruder (Stallman & Bari, 2017). There is little research on the etiology of violence during somnambulism, but Stallman & Bari suggest a biopsychosocial model with multiple potential risk factors. Diagnosis of somnambulism is typically based on the patient’s clinical history but polysomnography can also be employed. In Parks’ case, doctors took a thorough history and also administered two overnight polysomnograms (Broughton et al., 1994).
Broughton et al. (1994) unfold Parks’ story in their case report. In the months leading up to the attack, Parks had been facing high gambling debts and got fired because he was caught embezzling money from his workplace. The stress from this situation had been creating issues with his sleep schedule. Moreover, he and his wife had just welcomed their newborn daughter, which caused more stress and sleep deprivation. On the night of May 23, after an argument with his wife, Parks went to bed. He had made a plan to swallow his embarrassment and explain his financial situation to his parents-in-law, with whom he was close, the following day. But the next thing he knew, he was staring at the face of his dead mother-in-law.
Parks was charged with murder and attempted murder. In trial, he pleaded not guilty via the insane automatism defense, meaning that although he did commit murder, he did not consciously form the intention to do so (Popat & Winslade, 2015). The doctors and neurologists who testified at the case claimed that Parks had a history of sleepwalking and that his propensity toward it was likely exacerbated by sleep deprivation as well as emotional distress and anxiety (Popat & Winslade, 2015). Evidence for this included the fact that on several psychological tests, Parks had scored high for depression and anxiety (Broughton et al., 1994). Parks was acquitted of all charges.
Do you know of another interesting true crime case with medical connections? Email Rachel Brill at rgbrill@gwu.edu.
References
Broughton R, Billings R, Cartwright R, et al. Homicidal somnambulism: A case report. Sleep (New York, NY). 1994;17(3):253-264. doi:10.1093/sleep/17.3.253
DynaMed. Sleepwalking. EBSCO Information Services. Accessed August 23, 2022. https://proxygw.wrlc.org/login?url=https://www.dynamed.com/condition/sleepwalking
Popat S, Winslade W. While You Were Sleepwalking: Science and Neurobiology of Sleep Disorders & the Enigma of Legal Responsibility of Violence During Parasomnia. Neuroethics. 2015;8(2):203-214. doi:10.1007/s12152-015-9229-4 https://proxygw.wrlc.org/login?url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4506454/
Stallman HM, Bari A. A biopsychosocial model of violence when sleepwalking: review and reconceptualisation. BJPsych Open. 2017 Apr 26;3(2):96-101. doi: 10.1192/bjpo.bp.116.004390. PMID: 28446961 https://proxygw.wrlc.org/login?url=https://www.cambridge.org/core/journals/bjpsych-open/article/biopsychosocial-model-of-violence-when-sleepwalking-review-and-reconceptualisation/0F22062014B3EA2002ADBE94A3FCF2C2
Zadra A, Desautels A, Petit D, Montplaisir J. Somnambulism: clinical aspects and pathophysiological hypotheses. Lancet Neurol. 2013 Mar;12(3):285-94. doi: 10.1016/S1474-4422(12)70322-8. PMID: 23415568. http://proxygw.wrlc.org/login?url=https://www.proquest.com/scholarly-journals/somnambulism-clinical-aspects-pathophysiological/docview/1319202693/se-2?accountid=11243
