One night in 1987, a Canadian man named Kenneth Parks drove for 14 miles from his house to his in-laws. He then broke in and made his way upstairs, bludgeoning his mother-in-law with a crowbar that he’d gotten from the boot of his car before stabbing her repeatedly to death. He then proceeded to choke and stab his father-in-law, who miraculously survived. Parks then drove himself to the police station and turned himself in.

It sounds like a fairly cut and dry murder case, but after going to trial, Kenneth Parks walked free. Thanks to a combination of a lack of motive, his consistent version of events, and data gathered from EEG readings, no charges were pressed against him because all evidence pointed to the unlikely and bewildering truth that Parks had been sleepwalking. It remains one of the most remarkable cases of homicidal sleepwalking in history.