A son of notorious Mexican drug kingpin “El Chapo” pleaded guilty Monday to U.S. drug trafficking charges, months after his brother entered a plea deal.

Known locally in Mexico as the “Chapitos,” or “little Chapos,” Joaquin Guzman Lopez and his brother, Ovidio Guzman Lopez, are accused of running a faction of the Sinaloa cartel. Federal authorities in 2023 described the operation as a massive effort to send “staggering” quantities of fentanyl into the U.S.

Joaquin Guzman Lopez pleaded guilty to two counts of drug trafficking and continuing criminal enterprise.

He and another longtime Sinaloa leader, Ismael “El Mayo” Zambada, were arrested in July 2024 in Texas after they landed in the U.S. on a private plane. Both men have previously pleaded not guilty to various drug trafficking, money laundering and firearms charges. Their dramatic capture prompted a surge in violence in Mexico’s northern state of Sinaloa as two factions of the Sinaloa cartel clashed.

As part of the plea deal, Joaquin Guzman Lopez admitted to helping oversee the production and smuggling of large quantities of cocaine, heroin, methamphetamine, marijuana and fentanyl into the United States, fueling a crisis that has contributed to tens of thousands of overdose deaths annually.

His defense attorney, Jeffrey Lichtman, commended both U.S. and Mexican authorities.

“The government has been very fair with Joaquin thus far," he told reporters after the court hearing. "I do appreciate the fact that the Mexican government didn’t interfere.”

In July, Ovidio Guzman Lopez became the first son of drug lord Joaquin “El Chapo” Guzmanto enter a plea deal. He pleaded guilty to drug trafficking, money laundering and firearms charges tied to his leadership role in the cartel. Legal experts called the plea deal a significant step for the U.S. government in their investigation and prosecution of Sinaloa cartel leaders.

Joaquin “El Chapo” Guzman is serving a life sentence after being convicted in 2019 for his role as the former leader of the Sinaloa cartel, having smuggled mountains of cocaine and other drugs into the United States over 25 years. The brothers allegedly assumed their father’s former role as leaders of the cartel.