During the last decade of Elvis Presley's life, he became increasingly dependent on his doctor George "Dr. Nick" Nichopoulos — who supplied the King with thousands of prescriptions.

In 1978, Billy Milligan became the first person to successfully use multiple personality disorder as a legal defense, though the debate surrounding his condition turned the case into a hotly-debated spectacle.

Known as the "Galveston Giant," Jack Johnson made history as the first African American to hold the world heavyweight boxing championship.

Built in 1953 as a hunting lodge, the "world's loneliest house" is located on an island five miles south of Iceland that's inhabited only by puffins.

Lisa "Left Eye" Lopes was the heart of TLC and one of the top rappers of the 1990s before she was tragically killed in a car crash in Honduras.

In 2014, the families of Robert Haney and Stephen Delicino were horrified when investigators searching Susan Monica's farm discovered the two men's partial remains on the property.

Ashley Ellerin spoke with Ashton Kutcher on the phone mere minutes before her neighbor Michael Gargiulo stabbed her 47 times inside her Hollywood home on February 21, 2001.

Tracy Edwards was 32 years old when he went home with Jeffrey Dahmer one night in 1991 and nearly became the serial killer's 18th victim. His life was never the same after.

Hannah Upp, who first disappeared in 2008 and then in 2013, has a rare condition known as dissociative fugue, and she hasn't been seen since she vanished in 2017.

Between 1985 and 2000, four bodies were found crammed into barrels in the woods of New Hampshire. Authorities believe they were victims of suspected serial killer Terry Rasmussen.