Mario Cárdenas Guillén is the brother of the Mexican drug lord who was the former leader of what group?
Osiel Cárdenas Guillén Osiel Cárdenas Guillén (born May 18, 1967) is a former Mexican drug lord and the former leader of the Gulf Cartel (Spanish: "Cártel del Golfo" ) and Los Zetas. Originally a mechanic in Matamoros, Tamaulipas, where he was born, he entered the Gulf Cartel by helping Juan García Abrego, the capo at the time; when García Ábrego was arrested in 1996, some infighting erupted within the cartel. Osiel Cárdenas eventually took control by killing his friend and contender Salvador Gómez, earning Cárdenas the nickname ""El Mata Amigos"" (The Friend-Killer).
Infighting in the Gulf Cartel The infighting in the Gulf Cartel refers to a series of confrontations between the Metros and the Rojos, two factions within Gulf Cartel that engaged in a power struggle directly after the death of the drug lord Samuel Flores Borrego in September 2011. The infighting has lasted through 2013, although the Metros have gained the advantage and regained control of the major cities controlled by the cartel when it was essentially one organization.