Extreme Brotherhoods

In the maximum-security prison world of murderers, they are the most feared. With nicknames like "The Beast" and "The Hulk," The Aryan Brotherhood are the most violent criminals behind bars. National Geographic goes behind bars to unveil the secrets of the vicious gangs of white supremacists in prisons. Jailhouse interviews and surveillance footage reveal their deadly tactics.

See how this Islamic terrorist network continues to morph, selects and trains militants to blend into Western society, and inspires a global jihadist movement. Meet men who know and have fought with Osama bin Laden and find out why he's still at large.

In Greensboro, North Carolina, an argument over a song playing on the jukebox at a Mexican restaurant ends with two brothers dead--shot dead at point blank range. The culprit is a member of the notorious transnational gang MS-13. How did a gang that started in Los Angeles, California in the mid-1980s end up responsible for the murder of two innocent men in Greensboro, North Carolina? The search for answers leads deep inside the U.S. Immigration and Customs Enforcement Agency (ICE). Could the American government's war on transnational gangs, ironically, be making them stronger and more deadly?