Most people associate criminal charges with intentional actions — decisions made while someone is awake, aware, and in control. But what happens when a person commits an act while asleep and has no memory of it afterward? Surprisingly, it has happened, and there is a legal defense for it.

In a recent episode of the Just Criminal Law video series, criminal defense attorney Christina Williams and legal storytelling specialist David Mann explored this unusual area of law and how it has played out in real cases.

Real Case: A Sleepwalking Homicide

One of the earliest cases involving this type of defense involved a man charged with murder after killing his father-in-law while sleepwalking. He left his home, walked to his in-laws’ house, and attacked his father-in-law in front of his mother-in-law — all while asleep.

When he woke up, he was horrified and had no memory of the incident.

At trial, medical experts testified that he was in a parasomnia state — a sleep disorder involving complex behaviors during sleep, similar to sleepwalking. The court allowed his attorney to raise what’s known as an automatism defense, meaning the defendant’s actions were involuntary due to a state of unconsciousness.

The jury believed him, and the case became a landmark example of how sleep disorders can intersect with criminal law.

What Is Automatism?

Automatism refers to involuntary behavior during a state in which a person’s brain is not fully conscious, such as:

• sleepwalking
• seizures
• dissociative states
• certain medical or neurological conditions

Crucially, a person in this state is not capable of forming intent — which is required for most criminal charges.

A Modern Twist: “Sexsomnia” and Criminal Charges

During her career, Christina Williams encountered two back-to-back cases involving something even more unusual: sexsomnia.

Sexsomnia is a recognized parasomnia where a person engages in sexual behavior while asleep and later has no memory of it. It can involve actions that appear intentional from the outside, even though the person is unconscious.

In these cases, the accused individuals were facing sexual misconduct allegations. To defend them, Christina brought in sleep experts and conducted medical evaluations to determine whether their actions were the result of involuntary sleep behavior.

In one case, the client had a documented history of sexsomnia confirmed by his spouse, along with conditions like sleep apnea and narcolepsy. He sought medical evaluation, was diagnosed by a specialist, and the defense was compelling enough for prosecutors to offer a favorable deal that avoided trial and ultimately led to dismissal.

Sleep States vs. Legal Responsibility

Understanding why this is possible requires understanding how sleep works.

Sleep isn’t one fixed state — it cycles through different depths:

• Light sleep
• REM sleep (dreaming)
• Deep sleep

Experts compare these transitions to moving between floors on an elevator. Most people move smoothly between them, but parasomnia sufferers can get “stuck between floors,” where parts of the brain are asleep while the body remains active.

During those episodes, individuals may:

• walk
• talk
• drive
• cook
• eat
• or engage in sexual behavior

all without conscious awareness.

Because criminal law requires intent, the question becomes: Was the person’s brain capable of forming intent at the time?

Raising an Automatism Defense Is Not Simple

Cases like these are rare, and they’re complex. They typically require:

✔ expert testimony
✔ medical evaluations
✔ sleep studies
✔ documented history
✔ thorough legal preparation

Additionally, the defense must be formally raised well in advance so prosecutors can prepare.

What If This Happens to You?

Most assaults, sexual misconduct, and violent crimes do not occur during sleep. But for those rare cases where behavior during unconsciousness becomes a legal issue, the right defense strategy can make all the difference.

Being charged with a crime you don’t remember — or that happened while you were not truly conscious — can be devastating. It can also be deeply misunderstood by others.

That’s why these cases demand experienced legal representation, expert involvement, and careful investigation.

Charged With a Crime in Wyoming? We Can Help.

At Just Criminal Law, we represent clients facing complex and serious criminal charges, including cases involving unusual defenses like automatism.

If you or a loved one has been accused of a crime, don’t face the system alone. Contact us today to discuss your situation and learn your options.