Federal prosecutors in Chicago announced Thursday that a high-ranking member of the Sinaloa cartel—who is also the son of one of the ring’s leaders—has been giving information to government authorities. The plea agreement, which was unsealed on Thursday, shows that Jesus Vicente Zambada Niebla pleaded guilty in April 2013 to one count of conspiracy to possess with intent to distribute multiple kilograms of cocaine and heroin between 2005 and 2008. Zambada describes himself as a “trusted lieutenant” of his father, Ismael “El Mayo” Zambada-Garcia, who is not in custody. Zambada-Garcia is considered a close ally of the infamous Joaquin “El Chapo” Guzman. There is no indication that Zambada’s information helped lead to the capture of “El Chapo” this year, but court records show that Zambada objected to the agreement being unsealed.