Understanding the Sleepwalking Defense

What Is a Sleepwalking Defense?

Sleepwalking is a sleep disorder characterized by complex behaviors performed during sleep, often without awareness or memory of the events. A sleepwalking defense, also known as automatism or somnambulism defense, is a legal strategy used in criminal cases where the defendant claims to have committed an unlawful act while in a state of unconsciousness due to sleepwalking. This defense argues that the accused lacked the necessary mental state (mens rea) to be held criminally responsible for their actions.

In legal contexts, the sleepwalking defense falls under the broader category of automatism defenses. When successfully argued, it can lead to acquittal or reduced charges, as the court may determine that the defendant was not in control of their actions and, therefore, cannot be held fully accountable.

To determine the credibility of a sleepwalking defense, the following factors will have to be considered:

• Evidence of sleepwalking during the crime. Was there any direct evidence, such as witness testimony or surveillance footage, that suggests the defendant was sleepwalking?
• Time between falling asleep and the crime. How long had the defendant been asleep before the crime occurred? A longer period of sleep might make a sleepwalking defense more plausible.
• Medical factors. Does the defendant have a history of sleepwalking or other sleep disorders? Medical records can provide valuable evidence.
• Trigger factors. Were there any known triggers, such as stress or sleep deprivation, that could have made the defendant more susceptible to sleepwalking?
• Circumstantial evidence. Is there any other evidence, such as the defendant's behavior before or after the crime, that supports or contradicts the sleepwalking defense?

Even if a defendant can prove that they were sleepwalking, they may still be held liable if they failed to take reasonable precautions to prevent harm. For example, a chronic sleepwalker who knows they are prone to sleepwalking might be expected to take steps to secure their home or avoid potentially dangerous situations.

Cases Where the Sleepwalking Defense Was Used

Notable cases where the sleepwalking defense was invoked include:

• Massachusetts v. Tirrell (1846). This case is considered one of the earliest recorded instances of a sleepwalking defense in the United States. Albert Tirrell was accused of murdering Maria Bickford, a woman with whom he had been romantically involved. Tirrell's lawyer, Rufus Choate, argued that his client had a history of sleepwalking and may have committed the crime while in a somnambulistic state.
• Regina v. Parks (1987). This landmark Canadian case involved Kenneth Parks, a 23-year-old man who drove 23 kilometers from his home to his in-laws' house, where he attacked them with a tire iron, killing his mother-in-law and severely injuring his father-in-law. Parks then drove to a police station and turned himself in, claiming he had no memory of the events. His defense team argued that Parks, who had a history of sleep disorders, was sleepwalking during the entire incident. After extensive testimony from sleep experts and a thorough examination of Parks' personal and medical history, the jury acquitted him of murder and attempted murder. This case set a significant precedent for the sleepwalking defense in Canada and influenced similar cases internationally.
• Pennsylvania v. Ricksgers (1994). Joseph Ricksgers was charged with assaulting his wife after an incident where he allegedly tried to push her out of a second-story window. Ricksgers claimed he had no recollection of the event and was sleepwalking (because of his sleep apnea condition) at the time. The jury ultimately found Ricksgers not guilty by reason of unconsciousness due to sleepwalking, marking another successful application of this defense.
• California v. Reitz (2001). Stephen Reitz was accused of murdering his wife by stabbing her 44 times in their home. Reitz claimed he had no memory of the incident and believed he must have been sleepwalking. His defense team presented evidence of his long history of sleepwalking, including incidents where he had driven a car and prepared meals while asleep. They also argued that Reitz had recently stopped taking antidepressant medication, which may have exacerbated his sleep disorder. Despite the brutal nature of the crime, the jury found Reitz guilty because evidence of his violent history was more convincing than the sleepwalking defense claim.

The sleepwalking defense remains controversial and is often met with skepticism. Its successful application typically requires extensive expert testimony and evidence to support the claim of unconscious behavior during the commission of the crime.

Discuss Defense Strategies With Us

Corrigan Welbourn Stokke, APLC recognizes that one of our key responsibilities is to help clients understand and explore various defenses that might apply to your case. From the sleepwalking defense to entrapment, lack of evidence, self-defense, and other strategies, our team can use your case specifics to help you negotiate a plea or litigate a case using defense tactics.