William Leslie Arnold was just 16 years old in 1958 when he killed his parents and buried them in the backyard after they refused to let him borrow the family car to take his girlfriend to a drive-in movie showing of The Undead.

Arnold went about his life in and around Omaha, Nebraska, telling everyone – even family members – that his parents had taken a trip. Two weeks later he was arrested, confessed to the killings and led investigators to his parents’ makeshift gravesite.

The following year he was sentenced to two life sentences in the Nebraska state penitentiary. And that – most people expected – should have been that.