In 68 C.E., Emperor Nero stabbed himself in the throat with a dagger as he heard the hoofbeats of the approaching centurions who were sent to arrest him for his extravagant spending and tyrannical behavior.

On September 1, 1983, Korean Air Lines Flight 007 accidentally traveled into Soviet airspace due to a navigational error and was shot down by air-to-air missiles, killing all 269 people on board.

Sherry Shriner amassed a cult following with her YouTube videos about "alien reptiles" — then her ideas inspired one of her followers to murder another.

For decades, ufologists have claimed that extraterrestrials experiment on humans with the military's help inside a secret base underneath the Archuleta Mesa in Dulce, New Mexico.

From 1965 to 1971, Pamela Courson stood by Jim Morrison's side as his girlfriend and muse — until his tragic death at age 27.

From an early age, Albert Francis "Sonny" Capone struggled under the weight of his father's last name. So he decided to change it — then disappeared to California.

Among the dead were weapons, tools, a pocket watch, and a medal of honor for fighting in the Spanish Civil War.

Known as "Pogo the Clown," John Wayne Gacy killed 33 young men and boys during the 1970s. Then, he became an admired painter on death row.

Genghis Khan is believed to have had so many children that some 16 million men alive today are directly descended from the Mongol emperor.

Michael Gacy is one of two children fathered by John Wayne Gacy and has remained an elusive figure ever since his father's 1978 arrest for killing 33 young men and boys.