Former Mexican cartel kingpin Ismael “El Mayo” Zambada has pleaded guilty to federal charges related to his role in the violent drug trade.

For years the operation flooded the U.S. with cocaine, heroin and other illicit substances.

The longtime leader in the Sinaloa cartel entered his plea Monday in a Brooklyn federal court.

Prosecutors have said they won’t seek the death penalty against the 75-year-old Zambada. He was arrested in Texas last year.

Prosecutors say that under Zambada's leadership and that of Joaquín “El Chapo” Guzmán, the Sinaloa cartel evolved from a regional player into the world’s largest drug trafficking organization.