David Berkowitz, known as Son of Sam, murdered six people in New York City from 1976 to 1977, claiming he received orders from a demon-possessed dog. He is one of the most notorious serial killers in America.

Ted Kaczynski is a mathematician best known for a campaign of letter bombs he sent as the 'Unabomber' over a nearly 20-year period, resulting in three fatalities.

Phil Spector is best known for writing several No. 1 hit songs, and for being convicted of the murder of Lana Clarkson.

A child from an Italian immigrant family, Al Capone, also known as "Scarface," rose to infamy as the leader of the Chicago Outfit, an organized crime syndicate during the Prohibition era.

Ottis Toole, serial killer and cannibal, confessed to killing more than a hundred people with his partner Henry Lee Lucas. Toole murdered John Walsh's son.

Henry Lee Lucas was a murderer best known for allegedly killing hundreds of people in the 1960s and '70s, though only three (including his mother) were confirmed.

Baby Face Nelson was a bank robber and killer in the 1920s and '30s, and a criminal associate of John Dillinger.

Sammy "The Bull" Gravano, a mobster turned government witness, is best known for testifying against his mafia associates in exchange for government protection.

Roy DeMeo is best known for his time in the New York mafia, especially the Gambino crime family.

Paul Castellano is best known for becoming the boss of the Gambino crime family in New York City.