Mexican cartel boss Ismael “El Mayo” Zambada, who was one of the United States’s most wanted drug lords, pleaded not guilty to murder and drug trafficking charges in federal court in New York on Friday.

Zambada, co-founder and leader of the powerful Sinaloa cartel, will stay in prison until his trial after he was arrested in July in New Mexico, a spokesperson for the U.S. Attorney’s Office for the Eastern District of New York said.