A Mexican drug cartel leader was sentenced to seven life terms after pleading guilty in U.S. federal court to drug trafficking and direct or indirect participation in 1,500 killings since 2008.

The U.S. Justice Department said in a press release that Jose Antonio Acosta Hernandez, leader of the Juarez cartel in the northern Mexican border state of Chihuahua, pleaded guilty Thursday to drug trafficking and “numerous acts of violence” in connection with the Barrio Azteca gang.