The Mara Salvatrucha, or MS13, is perhaps the most notorious street gang in the Western Hemisphere. While it has its origins in the poor, refugee-laden neighborhoods of 1980s Los Angeles, the gang’s reach now extends from Central American nations like El Salvador and through Mexico, the United States, and Canada. They rob, extort and bully their way into neighborhoods and have gradually turned to transnational crimes such as human smuggling and drug trafficking. Their activities have helped make the Northern Triangle -- Guatemala, El Salvador, and Honduras -- the most violent place in the world that is not at war. In October 2012, the US Department of the Treasury labeled the group a "transnational criminal organization," the first such designation for a US street gang.