Between 2007 and 2009, Anthony Sowell killed 11 women and hid their decomposing remains in his house and backyard, creating a foul stench that ultimately pervaded the entire neighborhood.

Known as "The Godfather" of the New Orleans Mafia, Carlos Marcello was a prime target of President Kennedy's campaign against organized crime.

The head of the Bonanno family from 1991 to 2004, Joey Massino became a government informant after being charged with multiple murders that could have led to the death penalty.

Known as "The Enforcer," Frank Nitti orchestrated dozens of murders for Al Capone before becoming the boss of the Chicago Outfit himself.

In 1985, 14-year-old Cinnamon Brown was ordered to kill her stepmother by her own father — so he could collect life insurance and marry his teenage sister-in-law.

After building a $900 million drug empire in 1980s Los Angeles, "Freeway" Rick Ross was sentenced to life in prison — but then he got out and reinvented himself.

For decades, Arturo Beltrán Leyva rose to power under the guidance of more notorious traffickers. But by the early 2000s, he was sick of working for his bosses — and set out to become a fearsome boss himself.

In 1999, Ricky McCormick's body was inexplicably found in a Missouri cornfield — along with two pages of coded notes that have never been deciphered to this day.

New York medical student Kathleen McCormack vanished without a trace in 1982 — and while she's presumed to be dead, her body has never been found.

After 14-year-old Natasha Ryan vanished in 1998, authorities believed that she was the victim of a serial killer. But five years later, she turned up alive and well at his murder trial.

In the chilling story that inspired Truman Capote's In Cold Blood, Perry Smith and his accomplice Richard Hickock murdered the Clutter family inside their home in Holcomb, Kansas in November 1959.