From Sleepwalking Artists to Accused Killers: New Scientific Discoveries Shed Light on the Mystery of Somnambulism

The Unbelievable Case of the Sleepwalking Killer

The chilling 1987 case of Kenneth Parks in Canada, who drove 22 km to his in-laws' home and committed a violent crime while allegedly asleep, has brought the severe consequences of somnambulism (sleepwalking) into sharp focus. Parks, who was financially ruined and suffering from stress, drove, entered a locked house, attacked his in-laws, and then drove to a police station to confess, yet claimed to have no memory of the events. His eventual acquittal on the grounds that he was sleepwalking and therefore lacked criminal intent established a landmark—and highly controversial—legal precedent worldwide.

What Happens in the Brain During Sleepwalking?

Medically, somnambulism is a sleep disorder that occurs during the deepest phase of rest, specifically NREM (Non-Rapid Eye Movement) Stage 3 sleep.

• Incomplete Awakening: Sleepwalking is a purely neurological phenomenon resulting from an incomplete awakening of the brain. Part of the brain—the area controlling movement—wakes up, while the part responsible for consciousness remains asleep.

• Motor Activity Without Awareness: This allows the person to perform complex motor activities like walking, sitting, or even cooking and driving, even though their sensory perceptions are largely shut down (they can't truly see, hear, or smell). They often have a blank expression and, critically, no memory of the event upon waking.

• The Sleep Cycle: Sleep occurs in cycles (approximately 90-110 minutes each), alternating between NREM (non-dreaming, deeper sleep) and REM (Rapid Eye Movement, where most dreams occur) sleep. Sleepwalking is triggered when the brain fails to smoothly transition out of the deepest NREM stage.

Triggers and Genetic Risk

Research suggests that genetics plays a significant role in determining who might experience sleepwalking, with children having a much higher chance if both parents have a history of the disorder.

Common triggers for somnambulism include:

• Sleep Deprivation: Lack of sufficient sleep is the biggest contributor.

• Stress and Anxiety.

• Obstructive Sleep Apnea (OSA): A breathing disorder that interrupts normal sleep cycles.

• Certain Medications: Sedatives, antidepressants, and antipsychotics can increase risk.

The Legal Minefield

In criminal law, a guilty verdict requires both the act of a crime and the intent (guilty mind) to commit it. Sleepwalking complicates this, as the body performs the act, but the mind is unconscious.

• Controversial Defense: While Kenneth Parks was acquitted, the sleepwalking defense is highly scrutinized by courts globally. Cases like that of Scott Falater, who murdered his wife, saw the jury reject the defense due to the purposive, complex, and covering-up actions he took, which were deemed inconsistent with a typical, unthinking sleepwalking episode.

• India's Landmark Case: In India, the 1957 Papathi Ammal case—where a young mother, allegedly sleepwalking, drowned her baby—established that somnambulism can potentially be considered "unsoundness of mind" under Section 84 of the Indian Penal Code, making it a valid, albeit challenging, legal defense.

Safety for Sleepwalkers

For individuals who experience sleepwalking, the greatest risk is accidental self-harm, such as falling down stairs or out of a balcony. Simple safety measures are paramount:

• Secure the Environment: Lock all doors and windows, use child-proof latches, and install safety gates on stairs.

• Remove Hazards: Keep sharp or dangerous objects out of reach.

• Do Not Wake Them: If a sleepwalker is encountered, do not try to startle or wake them abruptly. Instead, gently guide them back to bed using a quiet, calm voice.