Mexico took down a US citizen who rose to the upper ranks of the vicious Zetas cartel

Reuters/Tomas Bravo

The letter "Z," referring to the Zeta cartel, painted on a hill next to a toll booth on a freeway between Monterrey and Torreon, in the Mexican state of Coahuila March 13, 2010.

• Mexico took down another regional leader in the Zetas cartel.
• Jose Maria Guizar Valencia was one of 122 high-priority organized crime targets, and his capture comes as the cartel continues to splinter.
• He reportedly oversaw the Zetas' trafficking operations in southern Mexico, but it's not clear what effect his arrest will have on the cartel's operations.

Mexican marines and federal police captured Jose Maria Guizar Valencia, known as "Z43," on Thursday, taking down a high-ranking figure in the Zetas cartel who was considered one of the 122 most wanted people in Mexico.

Mexico's government minister, Alfonso Navarrete, praised Mexico's naval forces for their investigation and coordination with civil intelligence that led to the arrest.

Born in Tulare, California, in November 1979, Guizar eventually joined the Zetas, which was formed in the mid-1990s when members of Mexico's military and special forces joined the Gulf cartel as muscle. The Zetas broke away to form their own organization around 2010.

US State Department

After the death of Zetas cartel founder Heriberto Lazcano Lazcano in late 2012 and the arrest of his successor, Miguel Angel Treviño, in summer 2013, Guizar assumed control of his own Zetas faction based in southern Mexico, according to the US State Department, which offered up to $5 million for his arrest in 2014.

Guizar's power was concentrated in the states of Veracruz, Tabasco, and Chiapas, and he played a central role in the Zetas' activity in Guatemala, which has long been an arrival and transit point for drugs coming from South America.

"He was one of the top underbosses of the Zetas," Mike Vigil, former chief of international operations for the US Drug Enforcement Administration, told Business Insider.

"This guy steadily rose up the ranks, and he actually started as a hit man for the Zetas ... but he was groomed to handle logistics, to handle drugs that were smuggled into Guatemala and Honduras," and coordinate with other Zetas members to get drugs to the US, said Vigil, who detailed his experiences working undercover in Mexico in "Deal."

"This is a very good hit," Vigil said of the arrest. "It's a good feather in the hat of Mexican justice."

The State Department described Guizar as "his own entity" working with, but independently of, the Zetas faction headed by Alejandro "Omar" Treviño in the northern Mexican states of Tamaulipas, Nuevo Leon, and Coahuila. Omar Treviño is believed to have taken control of the cartel after the arrest of his brother, Miguel Angel Treviño, before Omar himself was arrested in March 2015.

Reuters/Edgard Garrido

Omar Treviño Morales, the leader of the Zetas drug cartel known as "Z-42," is escorted by soldiers during a media conference about his arrest in Mexico City, March 4, 2015.

"Guizar Valencia is responsible for the importation of thousands of kilograms of cocaine and methamphetamine to the United States on a yearly basis," the State Department said. He has been indicted on drug-trafficking charges in Texas and Virginia.

Guizar was reportedly on the list of the eight most wanted criminals in the state of Chiapas and based his operations in western Tabasco, where he oversaw drug trafficking between South and Central America and the US. He also ran protection rackets, extortion, and kidnapping in the area.

Sources in the Mexican navy have said Guizar was behind a wave of violence in southeast Mexico, including the Mayan Rivera, which includes Cancun and Playa del Carmen, and the border area between Chiapas and Guatemala.

The Zetas cartel has been present in Guatemala since at least 2007. A Zetas-run training camp stocked with high-powered weapons was found near the Mexican border in 2009. Otto Perez Molina - Guatemalan president from 2012 until his resignation and jailing in relation to a graft case in 2015 - said in 2013 that the Zetas controlled of two of the biggest drug routes in Guatemala and were fighting the Sinaloa cartel for control of the third.

REUTERS/Stringer

Police stand guard next to suspected members of the Zeta drug cartel near Coban in Alta Verapaz, Guatemala, December 20, 2010.

"Los Zetas, under the command of Guizar-Valencia, have murdered an untold number of Guatemalan civilians during the systematic overtake of the Guatemalan border region with Mexico during recent years," the State Department said in 2014.

The Zetas have also formed a relationship with members of Guatemala's vaunted and notoriously violent special forces, known as the Kaibiles, because the latter have "not just preparation, but discipline, and military training that could help [the Zetas] with illegal activities," Perez Molina said at the time.

In the years since, other Guatemalan politicians have been accused of taking bribes from the Zetas in exchange for allowing them to operate there. (The Kaibiles, like Mexico's special forces, have received training from the US.)

Bernardo Montoya/Reuters

Suspected Zetas members at the Mexican navy's airplane hangar in Mexico City, October 7, 2011.

The Zetas' break from the Gulf cartel led to violent conflict between the two groups in Mexico, particularly in the northeast.

Areas in northeastern Mexico, especially areas along the border with the US and Tamaulipas, have also been the site of intense clashes between Gulf factions, while the Zetas are largely based in neighboring Nuevo Leon.

What effect Guizar's arrest will have on the Zetas' stability in southern Mexico remains to be seen. In recent years, the cartel has largely been run by plaza bosses, or regional leaders, Vigil said.

As in northern Mexico, Guizar's arrest could lead to more violence if a leadership vacuum opens and causes more internal feuding. It will likely further erode an organization that Vigil described as already "pretty well crippled."

"It'll probably cripple Zetas' ability to smuggle drugs through southern Mexico," Vigil said. Guizar "was a trusted member of cartel. He was probably going to rise to Zetas leadership," given his stature within the cartel, his knowledge of drug trade with Colombia, and knowledge of the Zetas' internal structure.

"He would've been a formidable leader with a little bit of time if he had been allowed to consolidate his power," Vigil said.