Former Gulf Cartel boss Mario Cárdenas Guillén, alias M1 or Metro 1, pleaded guilty to drug trafficking on Monday in a U.S. court. Details of the guilty plea are sealed, but Cárdenas Guillén was extradited to the U.S. in May to face a longstanding indictment that alleged between 2000 and 2012 he conspired to distribute cocaine.
“For decades, the Gulf Cartel has used intimidation and extreme violence to maintain control of its territories in northeast Mexico and smuggle deadly drugs into communities across the United States,” said DEA Administrator Anne Milgram after his extradition.
Cárdenas Guillén is part of a family that ran a prominent faction of the Gulf Cartel for more than two decades and has played a crucial role in much of the trafficking of drugs over the border in northeastern Mexico.
The Gulf Cartel rose to prominence in the 1980s and 1990s under the direction of Juan García Ábrego. But when García Ábrego was arrested in 1996, Osiel—Mario Cárdenas Guillén’s brother—took the helm of the organization in 1999 after a few years of bloody infighting and the arrests of other key leaders. Osiel Cárdenas Guillén allegedly cemented his place as boss after murdering another prominent member and close friend, earning the nickname “Mata Amigos”, or Friend Killer in English.
Under Osiel, the Gulf Cartel became notorious for recruiting Mexican army deserters to form an armed-wing of the cartel known as the Zetas, who would go on to become one of the most bloodthirsty and violent organizations in Mexico. Osiel Cárdenas Guillén was arrested in 2003 and extradited to the U.S. four years later, where he remains in prison.
His extradition created another power vacuum within the Gulf Cartel, as various factions fought for control of the group, and the Zetas slowly broke away to form an independent cartel. One of the factions of the Gulf Cartel was run by another brother of Osiel and Mario named Antonio Cárdenas Guillén, alias Tony Tormenta. That same year, Mario Cárdenas Guillén was released from Mexican prison in 2007 after serving over 10 years on drug charges, and rejoined Antonio in trying to keep the cartel in the family’s hands.
In 2010, Antonio Cárdenas Guillén died in an hours-long firefight with Mexican authorities that paralyzed the border city of Matamoros. His death led to further splintering within the organization, as Gulf Cartel members divided between a group led by Mario Cárdenas Guillén, and another led by a former top lieutenant.
Mario Cárdenas Guillén’s reign didn’t last long either. He was arrested in 2012 and has remained in Mexican prison until his recent extradition.
Still, the Cárdenas Guillén family continued to hold power in various forms. Mario was followed by a fourth brother, Homero, who reportedly died from a heart attack related to a surgery in 2014. After the arrests or deaths of the four Cárdenas Guillén brothers, a nephew named Alfredo Cárdenas Martínez, alias “El Contador” or the Accountant, became the boss of a powerful faction in northeastern Mexico. Alfredo has been arrested three different times since 2018, and since his latest arrest in March, U.S. authorities have pushed Mexico to extradite him like his uncles, Osiel and Mario.
But even if Mario and Alfredo are sent to prison in the U.S., the most dangerous of the clan may be on the loose again soon. Osiel Cárdenas Guillén is set to end his prison sentence on August 30, 2024 and will likely be deported immediately back to Mexico. What he will do once he gets home could determine the next chapter in Gulf Cartel history.