The White House called Caro Quintero “one of the most evil cartel bosses in the world” in a statement before his arraignment, where more than 100 Drug Enforcement Administration agents and other federal officials filled a large ceremonial courtroom.

Rafael Caro Quintero, nicknamed “El Narco de Narcos” (The Narco of Narcos) is the founder of the now defunct Guadalajara Cartel—one of the most powerful drug cartels of the 1980s that later splintered into various groups, including the Sinaloa Cartel, one of the world’s most powerful criminal organizations and drug cartels.

MEXICO CITY — Mexico extradited 29 alleged drug traffickers to the United States on Thursday, including Rafael Caro Quintero, a prized target long sought in the killing of a U.S. narcotics agent, and two leaders of the hyper-violent Zetas cartel,