MIAMI -

Barrio 18 was a group of Mexican migrants that organized into a gang in the 1980s. A murder started the three-decade-long cycle of revenge murders against the Mara Salvatrucha gang.

The Sinaloa cartel and Los Zetas have been known to work with the M-18 gang in Honduras. San Pedro Sula is at the cross roads of South American drug shipments on their way to the U.S. According to the U.S. State Department, Honduras is the first stop for the majority of the cocaine arriving to the U.S.

"The problem with MS-13 and 18th Street is that they are transnational," an FBI Special Agent familiar with the gang said. "They have huge populations in El Salvador, Guatemala, Honduras and they are starting to pop up in other countries."

The gang is also known as Calle 18, Mara 18, M-18, XV3, XVIII, 666, 99 and three dots. The colors of the gang are blue and black. Recruitment starts in elementary and middle schools. Gang members have been brutal toward girls as young as 11. Some are routinely gang-raped and forced into membership. The youngest work as "banderos" meaning they work as lookouts or spies. No one comes in or out of neighborhoods without they control without their knowledge.

The gang's franchises, known as "cliques" have spread like a virus through the Americas. They earn money from human trafficking, kidnapping, car theft, robbery, fraudulent document rings, illegal drug dealing, copyright infringement and weapons trafficking. The war tax they extort from the business sector includes street fruit vendors and Taxi drivers.

In Honduras, the gang has lawyers, architects and engineers among its members. The gang also employs its own medical team. Architects and engineers choose properties and adjust them for gang operations. They also remodel prison cells to make them comfortable for incarcerated members and their families.

The Chirizos gang, which also relies on extortion, drug trafficking and assassination services to generate revenue, used to belong to Barrio 18. Now they help patrons launder money.

HISTORIC TIMELINE | MORE ABOUT M-18