The Barrio Azteca, or Los Aztecas, is a Mexican-American gang originally based in El Paso, Texas. The gang was formed in the jails of El Paso in 1986 and expanded into a transnational criminal organization. They are currently one of the most violent gangs in the United States and are said to have over 3,000 members in the U.S. in locations such as New Mexico, Texas, Massachusetts and Pennsylvania and at least 5,000 members in Ciudad Juarez, Mexico.
In 2008, Barrio Azteca formed an alliance with La Línea, the armed wing of the Juárez Cartel, to fight off the forces of the Sinaloa Cartel, who were attempting to take over the drug smuggling routes in the area. The control of the routes in Ciudad Juárez, known as the "Juárez plaza," are vital for the drug trafficking organizations since they are the major illicit conduit into the United States. The DEA estimates that about 70% of the cocaine that enters the United States flows through the area. The gang's main source of income derives from smuggling drugs across the border from Mexico into the United States. They are also responsible for the distribution and sale of narcotics in and outside of prisons. Aside from drug trafficking, they have been charged with a number of different crimes.
The gang, which operates in the U.S. and Mexico, has morphed into a prime example of the "cross-border nature of Mexico's drug war." Members of the Barrio Azteca gang usually have U.S. citizenship, making them ideal cross-border killers that move back and forth across the U.S.-Mexico border.