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).
La Oficina de Envigado La Oficina de Envigado (English: The Office of Envigado ) is a drug cartel and criminal organization founded as an enforcement and collections arm of Pablo Escobar's Medellin Cartel. It operates throughout Colombia, but mainly in the cities of Medellín and Envigado. It also controls extortion, gambling, and money laundering businesses within the Valle de Aburra that surrounds Medellin. It positioned itself as the chief mediator and debt collector in drug trafficking disputes and maintained major connections with the "paracos" (Colombian paramilitaries) and guerillas.