You Snooze, You Lose: The Sleepwalking Defense

Everyday when the sun goes down, hundreds of millions people in the United States go to sleep. For most of those people, the act of sleeping occurs normally and they awaken the next morning to continue living productive lives. However, nearly seventy-five percent of adult Americans experience some form of a sleep disorder at least a few nights per week. Sleepwalking is one such disorder. The prevalence of sleepwalking in the general adult population is between one and fifteen percent.

Sleepwalking, which is also known as somnambulism, is a sleep disorder where sleepers make their way out of their beds and perform various actions while still asleep. In adults, sleepwalking is thought be correlated to an underlying psychological disorder, but this has yet to be confirmed.  

Sleepwalkers committing crimes is not unheard of. For instance, in Massachusetts v. Tirell, Albert Tirell stood accused of killing a prostitute and setting fire to the brothel and raised sleepwalking as a defense. In Fain v. Commonwealth, the defendant was asleep in a lobby and shot a porter who attempted to awaken him. In the 1987 case of Regina v. Parks, a man with a strong family history of parasomnia went to sleep, arose from bed, drove to his in-laws’ home, and attacked them. An example of a more recent sleepwalking crime was observed in 2011, where a judge recently accepted the defendant’s sleepwalking disorder defense and found him not guilty of assault.

Crimes committed during episodes of sleepwalking intersect with the criminal justice system because of criminal law philosophies on culpability. A criminal conviction requires both criminal action and criminal mental intent. “Generally, for a criminal defendant to be held culpable, the prosecution must prove that the defendant committed the act voluntarily. The basic premise of sleepwalking defenses is that sleepwalkers are not aware of their actions, and thus, should not be held culpable for actions beyond their control.”

Although rarely raised in American court, the sleepwalking defense has been brought forth in three forms: automatism, unconsciousness, and insanity. Automatism assumes that a sleepwalker’s bodily motions are beyond the sleepwalker’s waking control. The unconsciousness defense assumes that sleepwalkers are not capable of criminal intent because their minds are asleep and therefore lack the mental capacity to commit a crime.  An insanity defense to crimes committed during a sleepwalking episode argues that the defendant has a mental disease that prevents him from being cognitively aware of his actions and control those actions during the time of the offense.

Various jurisdictions across the United States will accept the sleepwalking defense under one of the aforementioned forms. Additionally, courts also must determine which party must bear the burden of proving that a sleepwalking episode occurred. Some courts such as the Kentucky Court of Appeals and the Supreme Court of Georgia require that a sleepwalking defense be used as an affirmative defense. Some jurisdictions, such as the Supreme Court of Wyoming and the Court of Appeals of North Carolina, place the burden of disproving a defendant’s claim of sleepwalking on the prosecution.

As a practitioner, regardless of whether you are prosecuting or defending a case with a sleepwalking component, one should first research whether this defense is recognized in their particular jurisdiction and which party assumes the burden. Sleepwalking as a defense is not a carte blanche defense. There are hurdles to pass in order to both successfully present and disprove a sleeping disorder as a defense. These hurdles lie in the medical science and additional factors surrounding sleepwalking. Defense attorneys need to make use of a defendant’s medical history related to sleepwalking episodes. This includes showing sleepwalking patterns, a family history of sleepwalking, environmental stressors, drug and alcohol use, and other medical conditions that are associated with sleepwalking. Prosecutors may attempt to point out that current medical information does support the grouping of sleepwalking into an automatism and unconsciousness defense. These prosecutors may argue that since sleepwalking episodes may be reduced through lifestyle changes, sleepwalking is not completely beyond the sleepwalker’s control. Most of all, practitioners on both sides must keep an eye on this issue. The practitioner that snoozes will lose because the progress made in this area through medical science and research will directly impact the criminal justice system.

By Stephane Plantin

Senior Editor, Criminal Law Practitioner

Photo by Herzi Pinki via Wikimedia Commons