The guy fighting the nurses, in the photo on the right, is asleep. Although usually considered a restful state, sleep, for a minority of people with specific disorders, is a trigger for violence.
Neurology journal Brain has just published a review paper (sadly locked) that discusses how violence can be triggered in the somnolent, noting that there are numerous cases of murders that have been ‘committed’ while unconscious.
The first known case is from the middle ages and apparently “relates to a Silesian woodcutter, who after a few hours of sleep woke up abruptly, aimed his axe at an imaginary intruder and killed his wife instead”.
Other more recent cases include:
Reported image of wild animal rising from floor and attacking child. Tried to defend child from beast, grabbing child instead and smashing him against the wall, killing him.
Vivid image of soldiers attacking daughter. Left house, grabbed axe, entered daughter’s room and ‘defended her’ by hitting twice with axe, killing her.
Dreamed that burglars had entered home and were killing family. Grabbed two guns and fired 10 shots, killing father and brother, injuring mother.
Image of two Japanese soldiers chasing him and wife through jungle. In his dream, he strangled one soldier and kicked another, killing his wife by strangling her instead.
You might be thinking that ‘I did it in my sleep’ is a convenient defence for someone who wants to get away with murder, but there are convincing criteria for deciding whether it was a genuine sleep attack.
The person need to have a confirmed sleep disorder, usually previous violence in sleep confirmed by video recording, as the picture above shows. The brief act typically happens as the person falls asleep or is awoken. The act seems impulsive, senseless and without motivation.
The person reacts with horror when they awake, makes no attempt to escape and can’t remember what happened.
The main risk factor is the presence of a sleep disorder. For example, REM sleep behaviour disorder – where people cannot prevent themselves acting out their dreams, is known to be linked to violence in a minority of those affected. Other conditions know to trigger sleep violence in some include epilepsy, confusional arousal or dissociative disorder.
Although the article in Brain is locked, the same research team published an alternative review paper on sleep violence last year for the medical journal Schweizer Archivs für Neurologie und Psychiatrie.
If you’re not a German reader, don’t be put off by the name because the article is in English and is freely available online as a pdf.