Also known as The Brand, the Aryan Brotherhood started in California’s San Quentin State Prison in 1964.
The AB has grown from a gang with racist ideology to a moneymaking organization that resembles a traditional organized crime family, according to the FBI.
The gang runs protection rackets, extortion, drug trafficking and contraband smuggling, as well as assaults for hire inside and outside prisons.
The AB exists in dozens of states but is strongest in California and Arizona.
In the federal prison system, the FBI alleges its members make up less than one-tenth of 1% of inmates but are responsible for 18% of all prison murders.
Members are identifiable by their tattoos, which include Nazi and Viking imagery and, typically, a prominently displayed shamrock.