Mind & Brain Are Sleepwalking Killers Conscious? Some people commit violent acts while asleep. In seeking to understand their brain states, scientists and physicians are investigating the murky borders of consciousness By Francesca Siclari, Giulio Tononi and Claudio Bassetti THIS IS A PREVIEW. Buy this digital issue or subscribe to access the full article. Already a subscriber or purchased this issue? Sign In SAMUEL BRADLEY Getty Images On the morning of May 24, 1987, sometime after 1:30 A.M., a 23-year-old Canadian named Kenneth Parks drove 14 miles to his in-laws' home, strangled his father-in-law to the point of unconsciousness, and beat and stabbed his mother-in-law to death. A year later he was acquitted of both assault and murder. After a careful investigation, specialists reached the astonishing conclusion that Parks had been sleepwalking—and sleep driving and sleep attacking—during the incident. This story inspired a 1997 made-for-television movie, The Sleepwalker Killing, starring Hilary Swank as Parks's wife. Although such extreme cases are rare, unintended acts of violence during sleep are quite common among those with sleep disorders. In a 1995 study of 64 sleep clinic patients suffering from sleepwalking or sleep terrors, more than half exhibited harmful behavior during sleep. An analysis at a different clinic that same year concluded that 70 percent of their 41 sleepwalking patients acted in a potentially injurious way. THIS IS A PREVIEW. Buy this digital issue or subscribe to access the full article. Already a subscriber or purchased this issue? Sign In Buy Digital Issue $7.95 Add To Cart Browse all subscription options! Subscribe ADVERTISEMENT Scientific American is a trademark of Scientific American, Inc., used with permission © 2015 Scientific American, a Division of Nature America, Inc. All Rights Reserved.