Home base: Tijuana, Mexico
Criminal activities: Drugs and arms (transportation and distribution), human smuggling, murder, extortion, prostitution
Formed in the 1960s in the Mexican border town of Tijuana, the Solo Angels have spread into the American Southwest but retain deep ties to Southern Californian street gangs, including one of the most feared gangs in the world: Mara Salvatrucha, or MS-13. The Solo Angels enjoy good press once a year during their Tijuana Toy Drive; otherwise, they're one of the Hells Angels' few allies, and have been associated with the Mongols, who have a bloody, ferocious rivalry with the Hells Angels.