9 "Criminal Minds" Episodes That Are Based on Very Creepy True Stories

In this creepy episode, a murderer sends a tape to the BAU himself, begging them to help him stop killing. It's based on the case of William Heirens, also known as the "Lipstick Killer" after he left a message pleading for someone to stop him written in lipstick at one of his murder scenes. The Lipstick Killer was also referenced in the pilot episode of "Criminal Minds," which similarly focused on a serial killer abducting and killing young women. The fictional killer's motivations, however, are very different from the real Heirens, who later claimed innocence and even asserted that an alternate personality or imagined persona "made him" commit the crimes.