Danny Casolaro was investigating a number of conspiracy theories involving everything from Ronald Reagan’s election to the Iran-Contra affair when he was found dead under strange circumstances on August 10, 1991.

In November 2004, 21-year-old Christopher Porco chopped up his parents as they slept in their bed, leaving his father dead and his mother missing an eye and part of her skull.

Beginning in 2010, investigators uncovered 16 corpses — mostly young women — who had been killed over a period of at least 14 years and discarded across New York’s Gilgo Beach. Authorities believe that they may have been victims of the mysterious Long Island Serial Killer.

On May 31, 2014, sixth graders Morgan Geyser and Anissa Weier tried to murder their friend Payton Leutner in the woods of Wisconsin — to please Slender Man.

Yetunde Price was the loving half-sister of tennis champs Venus and Serena Williams — but then she was suddenly killed in a drive-by shooting in 2003.

In 2016, Kala Brown was chained up for two months inside a homemade prison made by serial killer Todd Kohlhepp, also known as the "Amazon Review Killer."

Tilly Devine started out as an impoverished sex worker in the London slums before she moved to Australia, opened a string of successful brothels, and became one of the most violent crime bosses in Sydney.

Dubbed the "Girl in the Closet," Lauren Kavanaugh was isolated and abused mentally, physically, and sexually by her mother and stepfather between the ages of two and eight.

Frank Lloyd Wright built a house called Taliesin as a refuge for his mistress Mamah Borthwick. But in 1914, one of his servants butchered her with an ax and burned the Wisconsin home down.

When the Five Families refused to allow him into the drug trade, Frank Matthews became a kingpin in his own right — until he mysteriously vanished in 1973 with $20 million.

George Hodel was a notorious Los Angeles doctor whose sexual proclivities and surgical knowledge have led many to believe that he killed Elizabeth Short.