Alvin Karpis was a notorious American gangster, once the FBI's "Public Enemy No. 1", and a member of the infamous Barker-Karpis gang.
John Torrio was an influential American mobster, mentor to Al Capone, and pioneer of organized crime in Chicago during the Prohibition era.
Cole Younger was a notorious American outlaw and a prominent member of the infamous James-Younger Gang, known for their bank and train robberies in the post-Civil War era.
Frank Nitti was a notorious American mobster, enforcer and eventual boss of the Chicago Outfit, infamous for his criminal activities and connections to Al Capone.