Season 4 - Episode Guide

James "Whitey" Bulger is one of the most notorious organized crime bosses in American history.

Known as the Monster of Atwater Village, Timothy McGhee was the shot caller for the Toonerville gang; Timothy was an aspiring rapper who wrote lyrics about his gang life and hatred for cops, who was also feared among many in Los Angeles.

Vincent `Vito' Smothers was one of Detroit's most notorious killers but he didn't start out that way; Smothers was born and raised on the wrong side of eight mile and started out an honors student until the lure of the dollar enticed him.

In Houston, a city where the sex trade is booming, an organization was ruled by one madam, Hortencia Medelles-Arguella; Hortencia was the mastermind of the biggest sex ring to be busted in Texas.

Marvin Mercado, aka ``Shy Boy,'' and his brother, Pierre aka ``Boo Boo'' were major players in the violent street gang, the Asian Boyz in the 1990's.

Ross William Ulbricht, the man behind Silk Road, an online marketplace for illegal drugs.