Osiel Cárdenas Guillén, the former leader of the Gulf Cartel and founder of the violent Zetas gang, was released from a U.S. prison on Friday after serving most of his 25-year sentence for drug trafficking and related charges. He was handed over to U.S. Immigration and Customs Enforcement (ICE), where he remains in custody pending potential deportation to Mexico. Cárdenas Guillén faces outstanding warrants in Mexico and is likely to be detained upon arrival, as he oversaw a drug trafficking empire notorious for extreme violence. His criminal legacy includes the transformation of drug trafficking tactics, leading to unprecedented brutality in Mexico's drug wars. The Biden administration is reportedly considering turning him over to Mexican authorities shortly. Former DEA agent Leo Silva criticized Cárdenas for his role in escalating organized crime and terror in Mexico.