David Berkowitz, a serial killer also known as the "Son of Sam," was incarcerated in the Attica Correctional Facility, an Upstate New York super max prison, when he predicted a murder. Written off as just a made-up story, nobody listened to Berkowitz until his exact prediction played out.
On the early morning of Halloween in 1981, while staying in their Manhattan home, 39-year-old Ronald Sisman and 20-year-old Elizabeth Platzman were beaten and shot to death. According to Reader's Digest, Berkowitz had described a cult carrying out this massacre, and even described the exact apartment layout to a T.
It is unclear if Berkowitz's prediction was merely a coincidence, and to this day, the murder remains unsolved.