The Zetas started out as the enforcement arm of Mexico 's Gulf Cartel , but later split off and formed their own drug-trafficking organization . Mario Armando Ramirez Trevino was captured near the Mexico border . He is a suspected leader of U.S. 's the Gulf Cartel , two of the major drug-trafficking groups . The group has suffered a series of blows recently , including the arrests of one top lieutenants .
Mario Armando Ramirez Trevino was captured near the Mexico border . He is a suspected leader of U.S. 's the Gulf Cartel , two of the major drug-trafficking groups . The group has suffered a series of blows recently , including the arrests of one top lieutenants .