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Homicidal somnambulism, literally homicidal sleepwalking and colloquially known as sleepwalking murder, is the act of killing someone during an episode of sleepwalking. Occasionally, sleepwalkers kill people, usually a family member, during their sleepwalking act. There have been several rare cases in which an alleged act of homicide has occurred, and the prime suspect may have committed the act while sleepwalking. About 69 cases to date have been known.[1] These cases have fared in various ways in the judicial system.

Cases[edit | edit source]

Historic cases[edit | edit source]

Polish physician Jan Jonston reported a case which occurred around 1630 where an inhabitant of Paris while asleep got up, took his sword, swam across the river Seine and killed a man he had planned to murder the day before. After that, he crossed back the river to his home, eventually getting to his bed, without awaking.[2]

Parks case[edit | edit source]

In 1987, Kenneth Parks was a married 23-year-old man with a 5-month-old daughter. He had a very close relationship to his in-laws, with his mother-in-law referring to him as "her gentle giant." The summer before the controversial events, he developed a gambling problem and fell into deep financial problems. To cover his losses, he took funds from his family's savings and then began to embezzle at work. Eventually, in March 1987, his actions were discovered, and he was fired from his job. On May 20, he went to his first "Gamblers Anonymous" meeting. He made plans to tell his grandmother the following Saturday (May 23) and his in-laws on Sunday (May 24) about his gambling problems and financial difficulties.

In the early morning hours of May 23, 1987, Parks reportedly got up (not awoke) from his sleep, drove roughly 23 km to his in-laws' home and broke in, assaulted his father-in-law and stabbed his mother-in-law to death. After all this, he managed to drive himself to the police station. Aside from a few isolated events, the next thing he could recall was being at the police station asking for help, saying “I think I have killed some people…my hands.”

Parks’ only defense was that he was asleep during the entire incident and was not aware of what he was doing. Naturally, nobody believed it, even sleep specialists were extremely skeptical. However, after careful investigation, the specialists could find no other explanation. Parks’ EEG readings were highly irregular even for a parasomniac. This combined with the facts that there was no motive, that he was amazingly consistent in his stories for more than seven interviews despite repeated attempts of trying to lead him astray, that the timing of the events fit perfectly with the proposed explanation, and that there is no way to fake EEG results, Parks was acquitted of the murder of his mother-in-law and the attempted murder of his father-in-law.

  • all information was taken from a study conducted by R. Broughton, et al.[3]

Falater case[edit | edit source]

In 1997, Scott Falater was accused of murdering his wife by stabbing her 44 times. According to an eyewitness, Falater was also seen holding his wife’s head under water. When he was tried, the prosecution claimed that after the murder had been committed, Falater changed his clothes, put the murder weapon in a Tupperware container, put the container in a trash bag with his boots and socks, stashed the bag in the spare tire well in the trunk of his car, and took and hid all the items that showed that he was the person who killed her. On June 18, 1999 a prosecution expert testified that that Falater's actions were "too complex" to have been carried out while sleepwalking. A week later, Scott Falater was found guilty of first degree murder and sentenced to life in prison without chance of parole.[4]

Causes[edit | edit source]

It has been suggested that sleepwalking and other forms of parasomnia occur from deep non-REM slow wave sleep (SWS). It is caused by an inappropriate physiological event where the brain tries to exit SWS and go straight to wake. In normal sleep, the brain transitions from sleep either from stages 1 or 2 of NREM or REM sleep, but almost never from SWS. As a result, the brain gets “stuck” between a sleep and wake state.[5] In the case of Kenneth Parks, his EEG showed that his brain tries to wake from SWS 10 to 20 times a night. Needless to say, this is an incredible number compared to normal sleepers who almost never experience this. Nobody is sure why some people will commit murders in their sleepwalking episodes, but it seems reasonable to assume that many conditions must be met. Using Kenneth Parks as an example again, he was planning to go to his in-laws’ residence the next day, he was stressed and depressed from marital and financial troubles, and he had been sleep deprived because he couldn’t get any sleep the night before.[6]

See also[edit | edit source]

References[edit | edit source]

  1. BBC NEWS | UK | How sleepwalking can lead to killing
  2. Jan Jonston, Thaumatographia Naturalis, Amsterdam, 1630 cited in J.A.S. Collin de Plancy, Dictionnaire Infernal, Paris, Mongie, 1818
  3. Broughton et al. Homicidal Somnambulism: A Case Report. Sleep (1994); 17(3):253-64
  4. Martin, Lawrence. Can sleepwalking be a murder defense? 26 Apr. 2008. <>.
  5. Bassetti et al., Lancet (2000); 356: 484–485
  6. Broughton et al. Homicidal Somnambulism: A Case Report. Sleep (1994); 17(3):253-64
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