A son of notorious Mexican drug kingpin “El Chapo” pleaded guilty Friday to U.S. drug trafficking charges. He is the first of El Chapo’s sons to enter a plea deal.

It’s expected that Ovidio Guzmán López’s guilty plea agreement will pave the way to further federal prosecution of Sinaloa Cartel members.

The plea came at a vulnerable moment for the Sinaloa drug cartel, the organization Ovidio Guzmán López’s father helped found.