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).
Luis Fernando Sánchez Arellano Luis Fernando Sánchez Arellano (b. ca. 1977), commonly referred to by the alias El Ingeniero ("The Engineer"), is a Mexican suspected drug lord and former leader of the Tijuana Cartel, a drug trafficking organization based in Tijuana, Baja California. He competed with three other major cartels, the Juárez Cartel, the Gulf Cartel, and the Sinaloa Cartel, for the illegal drug corridors into the United States.