The son of one of Sinaloa cartel kingpin Joaquin "El Chapo" Guzman's closest associates has pleaded guilty to drug-trafficking charges in the US.

There are already signs the son is cooperating with US authorities, and he could provide them with detailed information about the cartel's inner workings.

The details he divulges could lead to more blows to the cartel's leadership and set off another, bloodier round of infighting.



Damaso Lopez Serrano, 29, pleaded guilty to drug-smuggling charges in a federal court in San Diego on January 10, admitting he oversaw the shipment of thousands of pounds of meth, cocaine, and heroin to the US.

The plea comes about six months after Lopez Serrano crossed the US-Mexico border at Calexico, California and turned himself over to US authorities, becoming the highest-ranking member of a Mexican cartel to ever surrender to the US, according to the US attorney's office.

Lopez Serrano admitted he held a leadership role in the cartel and pleaded guilty to the possession of firearms in relation to drug trafficking. He also pleaded guilty to drug-smuggling charges in a separate case in Virginia. He faces a mandatory minimum sentence of 10 years in prison and agreed to forfeit $1 million in cash.

His "conviction strikes a serious blow to the leadership of the Sinaloa cartel and its violent drug-trafficking activities," acting Assistant Attorney General John P. Cronan said. The potential fallout from Lopez Serrano's cooperation with authorities could ripple throughout Mexico's narco underworld.

'A virtual encyclopedia ... on the Sinaloa cartel'

Damaso Lopez Serrano, in an undated photo. Televisa/Twitter

Lopez Serrano is the son of Damaso Lopez Nuñez, a former Mexican security official who climbed the ranks of the Sinaloa cartel and eventually became the right-hand man to cartel chief Joaquin "El Chapo" Guzman. The younger Lopez, described as violent and flashy, was considered by some to be a potential successor to Guzman.

Lopez Serrano is already cooperating with US authorities, according to Mike Vigil, former chief of international operations for the US Drug Enforcement Administration.

"He can provide in-depth information on the current leadership of the Sinaloa cartel, to include the sons of 'Chapo' Guzman ... as well as 'El Mayo' Zambada and his sons," Vigil told Business Insider. "He can also provide information on corrupt public officials that are protecting the Sinaloa cartel."

"Damaso can provide information on the Colombian sources of supply for cocaine. He can provide provide information on the modes of transportation" used by the Sinaloa cartel to move drugs from South American to Mexico and then into the US, Vigil said. "He can also talk about the distribution network that they use here in the United States and who controls those networks."

"This guy is fully cooperating, so he's going to be debriefed on anything and everything," added Vigil, who recounted his experiences working undercover in "Deal." "So this guy will be a virtual encyclopedia for law enforcement on the Sinaloa cartel and other cartels that the Sinaloa cartel is allied with."

Mexican drug lord Joaquin "El Chapo" Guzman is escorted by soldiers in Ciudad Juarez, Mexico, during his extradition to New York, January 19, 2017. Mexico's Attorney General's Office/Handout via REUTERS

The indictment in Lopez Serrano's case was filed in August 2016 and unsealed in August 2017. The Justice Department described it as a milestone in a five-year investigation that has led to charges against more than 125 people.

Among those named in the indictment are Ismael "El Mayo" Zambada, Guzman's partner who is believed to be running the Sinaloa cartel, as well as two of his four sons — Ismael Zambada Sicairos, known as "Mayito Flaco," and Ismael Zambada Imperial, known as "Mayito Gordo." A third son, Serafin Zambada Ortiz, pleaded guilty to drug-trafficking charges in San Diego in September 2014.

Two of Guzman's sons — Ivan Archivaldo Guzman, known as "Chapito," and Jesus Alfredo Guzman, known as "El Gordo" — are also named.

Lopez Nuñez, who is believed to have helped Guzman escape prison in 2001, reportedly partnered with the Jalisco New Generation cartel to form one of at least three factions that fought for control of the Sinaloa cartel after Guzman was recaptured in Mexico in January 2016.

The "Damasos" were thought to have their own uniformed army, the "Damaso Special Forces." The younger Lopez was also believed to be the leader of an armed wing of the Sinaloa cartel.

The conflict over control of the cartel was blamed for pushing violence up in Sinaloa state throughout 2016 and early 2017.

Mexican officials also blamed Lopez Nuñez for violence on the Baja California Peninsula, particularly in Baja California Sur, which saw a more than 223% year-over-year increase in homicide victims between 2016 and 2017, the most in Mexico.

The faction led by Guzman's sons and backed by "El Mayo" Zambada appears to have won that struggle, which seems to have restored some stability to Sinaloa state.

'There will be many that will try to take over that void'

The elder Lopez was arrested in Mexico City in mid-2017, and the US is currently seeking his extradition. His capture left his son with neither allies nor refuge in Mexico.

Lopez Serrano "had no choice but to flee Mexico and turn himself into US authorities, because he was being hunted down the other members of the Sinaloa cartel and would've been killed if he decided to stay in Mexico," Vigil told Business Insider. "The only option that he has at this point in time to save himself is to name names and provide significant information on the cartel."

But the younger Lopez's ongoing cooperation with US authorities could allow the US and Mexico to put more pressure on the Sinaloa cartel. More turmoil within the cartel over its leadership or fighting for control of its immense resources and operations would almost certainly ripple throughout Mexico.

A Mexican marine looks at the body of a gunman next to a vehicle after a gun fight in Culiacan, Sinaloa state, Mexico, February 7, 2017. (AP Photo/Rashide Frias)

Zambada, who is believed to be about 70 years old and ill, "still apparently is holding on to the reins of the power within the Sinaloa cartel," Vigil said.

Lopez Serrano can likely provide authorities with valuable information about Zambada, including his communications methods, his patterns of movement, and the kinds of security precautions he takes.

It remains to be seen whether Mexico would extradite cartel suspects named by Lopez Serrano and indicted by the US, Vigil said. But, he added, if "Zambada is captured, I'm going to have to say that the Sinaloa cartel will immediately fracture between 'Chapo' Guzman's sons, Ismael Mayo's sons, and others within the Sinaloa cartel, and that is going to lead to more massive violence than Mexico has ever seen" during any previous period of cartel infighting.

"Sinaloa still remains the most powerful cartel," Vigil said, "and there will be many that will try to take over that void."