Mary Jane Kelly was an enigmatic figure with a mostly unverified story. What was clear, though, was the horrifying nature of her murder.

After fleeing Nazi Germany in 1938, William Hitler became an American citizen, changed his name to William Stuart-Houston, and joined the U.S. Navy, where he was awarded a Purple Heart during World War 2.

Mel Ignatow killed his girlfriend Brenda Sue Schaefer in 1988 and managed to get away with it. Two decades later, however, he met a grisly fate eerily reminiscent of that murder.

Tom and Eileen Lonergan went on a group scuba diving trip to the Coral Sea in January 1998 — before they were accidentally abandoned and never seen again.

One of the most calculating serial killers in British history, Graham Young started poisoning his victims when he was just 14 years old and kept a meticulous diary of his crimes.

An infamous punishment used to maintain order at sea in the 17th and 18th centuries, keelhauling was when sailors would be dragged under ships as punishment.

Operation Anthropoid, a secret plan to kill Reinhard Heydrich in 1942, was the only successful assassination of a top Nazi officer during World War II.

Literally translating to "rotting cheese," casu marzu is a traditional Sardinian pecorino made with sheep's milk — and filled with live maggots.

Tara Calico disappeared in Belen, New Mexico on September 20, 1988. A year later, two Polaroids of a tied-up woman were discovered in Florida — was it her?

Born in Plympton, Massachusetts in 1760, Deborah Sampson became a hero of the American Revolution after posing as a man to join the Continental Army.

In the late 1970s, serial killer Richard Chase murdered at least six people in Sacramento, California — and drank the blood of his victims.