“The Cartel Killed Anyone Who Refused to Work With Them”: How Los Zetas Built a Criminal Empire in Coahuila

Under the leadership of Miguel Ángel and Omar Treviño Morales, the so-called “Last Letter Cartel” controlled and operated every aspect of one of the country’s most coveted drug trafficking centers.

The Treviño Morales brothers forged their criminal empire with blood and lead.

Miguel Ángel and Omar Treviño Morales left Mexico one of the bloodiest periods in its history during their time leading Los Zetas. Although little more than a decade has passed since their respective arrests, the brothers, better known as El Z40 and El Z42, are set to face a trial in the United States that could leave them in prison for the rest of their lives.

According to reports by journalist Angel Hernández for MILENIO, on the morning of Tuesday, October 14, the former criminal leaders were presented before Judge Trevor McFadden in a federal court in Washington, DC, as part of the ongoing judicial process against them on charges related to organized crime, drug trafficking, money laundering, and firearms possession.

The US Attorney’s Office continues to gather incriminating evidence that could be released if the brothers go to trial. However, in recent years, various judicial proceedings against members of Los Zetas in the United States have revealed the brutality with which El Z40 and El Z42 operated, the same brutality that allowed them to forge a criminal empire in northeastern Mexico with blood and lead.

Coahuila: the coveted plaza

The origin of Los Zetas has a name and surname: Osiel Cárdenas Guillén. The former leader of the Gulf Cartel, determined to rise to the top of drug trafficking in Mexico, set about recruiting a group of elite soldiers who had deserted the Mexican Army to form his own armed wing in the late 1990s.

The objective was as simple as it was dangerous. That troop was to protect the so-called “Friend Killer” and his lucrative drug trafficking business from rival criminal organizations and authorities seeking to interfere with their interests.

What Osiel Cárdenas Guillén never expected was that his arrest would become imminent in 2003 and would leave a serious leadership succession problem that, coupled with the strengthening of his armed wing, would ultimately consolidate Los Zetas’ emancipation from the Gulf Cartel.

Thus, the criminal organizations that had been operating in alliance became enemies and began to fight for control of key locations for the trafficking of drugs, weapons, and migrants in northeastern Mexico, specifically in Tamaulipas, Coahuila, Nuevo León, and parts of Veracruz.

This criminal reorganization coincided with the rise of Miguel Ángel Treviño Morales, who, although already second-in-command, managed to consolidate his leadership after the assassination of Heriberto Lazcano, alias Z3.

While multiple splinter groups within the Gulf Cartel began to fight for control of key border cities in Tamaulipas, Los Zetas saw Coahuila, especially Piedras Negras, as a key border corridor for their drug smuggling operations to the United States.

Control of this location could only be in the hands of someone completely trusted by the leader of Los Zetas, so it was assigned to his brother, Omar Treviño Morales, known as Z42. By 2011, Coahuila municipalities such as Allende, Piedras Negras, Nava, and Morelos were already under the Zeta yoke.

Corruption and self-government: the criminal empire

Between 2013 and 2016, at least eight members of Los Zetas who worked for Miguel Ángel and Omar Treviño Morales were tried in courts in Austin, San Antonio, and Del Río for crimes including homicide, conspiracy to import drugs and weapons, and money laundering.

In each of these trials, various witnesses appeared before the courts. Their statements were compiled by the University of Texas School of Law and the Fray Juan de Larios Diocesan Center for Human Rights of Coahuila in a report that portrays how Los Zetas built a criminal empire in the state through two main elements: horror and corruption.

Both factors were exposed in the trial of Marciano Millán Vásquez, alias Chano, in San Antonio. Identified as a key commander of the Treviño Morales brothers in Piedras Negras, at least 12 people testified against him, including mid- and low-level drug traffickers, investment advisors, and money launderers.

One of these witnesses stated that Los Zetas once had complete control of states such as Nuevo León, Coahuila, Tamaulipas, Veracruz, Zacatecas, San Luis Potosí, and Puebla, manifesting this influence through the cartel’s influence over police forces, prosecutors’ offices, and other public officials.

To achieve this, the criminal organization employed two strategies. The first involved directly paying police officers and integrating them into the Los Zetas hierarchy, either to prevent them from interfering in their operations or to actively involve them. In the second, according to witnesses, the plaza boss in charge of the city controlled the police and its leaders.

“Campos explained how he began working with the cartel, trafficking weapons and drugs and gathering information for them while working as a police officer in Coahuila. He and other police officers monitored the trafficking and passed information to Los Zetas about individuals coming and going from Piedras Negras […] Los Zetas maintained control over the police, ensuring their cooperation through intimidation and force. If a police officer refused to do certain things, Los Zetas would threaten him and his family,” the University of Texas Law School report states.

The testimony gathered in the three trials alludes to the links between state and municipal security agencies and Los Zetas, for whom they worked to provide protection for their operations and shipments, as well as for their rivals. However, some also report that not all authorities, especially federal ones, were under their influence.

“Uribe stated that members of Los Zetas took additional precautions to avoid detection by the marines, including flying in government helicopters, using BlackBerry phones, and coordinating a surveillance system. Plaza leaders also rotated between the different territories under Zeta control for protection,” the report adds.

The corruption with which Los Zetas operated extended to the Piedras Negras Penitentiary, which they took control of and established self-government. José Luis Rodríguez, a mid-level drug trafficker who operated for the criminal organization, claimed that the prison was used to fix cars with secret compartments for drug trafficking, drug dealing, and even as a hideout for members and leaders wanted by the Navy or the Federal Police.

Another witness, involved in money laundering, testified that members of Los Zetas who were inmates could come and go from the prison as they pleased. Those sentenced had access to drugs, alcohol, weapons, televisions, cell phones, refrigerators, women, and parties, as well as the comfort of having their own rooms.

“Witness A also made statements about the relationship between Los Zetas and state prosecutors. She indicated that a hitman with whom she was in a romantic relationship paid $167,000 pesos to be released from prison and to have the charges against him dismissed. According to Witness A’s testimony, other people also paid to be released,” reads the second part of the University of Texas report.

In September 2012, Los Zetas orchestrated a mass breakout from the Piedras Negras prison to recruit new members to help them maintain control of the plaza in the face of the threat posed by a rival cartel. Approximately 130 inmates were recruited, some forcibly, after leaving the prison through a tunnel that connected to a vacant lot.

“Los Zetas often announced they would take control of any city or plaza they wanted and forced the residents of that city to work for them. If people didn’t report to Los Zetas in the plazas, they would be killed […] Another statement claimed they frequently appeared in Piedras Negras to forcibly recruit new members. The cartel killed anyone who refused to work with them,” it explains regarding their recruitment dynamics.

The names of various state public officials, as well as meticulous money laundering schemes, were also described by witnesses during the three trials against members of Los Zetas. These factors, while exposing the level of corruption, also strengthened their criminal structure.

The Los Zetas massacres in Coahuila

The power and impunity that Los Zetas achieved in Coahuila made the state the scene of two brutal massacres: the Allende massacre and the Piedras Negras massacre. According to various testimonies and investigations recorded in court documents, both events consisted of a series of systematic murders and kidnappings that Los Zetas committed in retaliation after some of their highest-ranking members voluntarily surrendered to the United States to cooperate as witnesses in federal trials.

The University of Texas Law School report estimates that more than 300 people allegedly linked to those who fled to the United States were killed or disappeared during March and April 2011.

“When Poncho Cuellar fled to the United States, Z40 and Z42—the Treviño brothers—and their hitmen took revenge by massacring anyone linked to Cuellar […] Rodríguez, a drug trafficker, claimed that the death sentence included men, children, and the elderly who were linked in one way or another to Poncho Cuellar, even those not involved in drug trafficking,” it explains regarding the atrocities committed by Los Zetas.

Adolfo Efrén Tavira Alvarado, identified as the sole survivor of the Piedras Negras massacre, recounted how cartel members entered his home armed with weapons, kidnapped him, and took him handcuffed to a place where Z40 and Z42 were with their hitmen. At the scene, he described, more than 30 people were kneeling, being interrogated about Cuéllar before the Zetas leaders and their subordinates shot them. “They were killing them in cold blood. And they grabbed their bodies and threw them into pickup trucks,” Tavira recalled.

The Allende and Piedras Negras massacres were just the tip of the iceberg of the brutality with which Los Zetas operated under the command of the Treviño Morales brothers. Testimony from three trials retrieved by the Texas Law School described how members of the criminal organization disposed of their victims’ bodies.

One of the witnesses to the atrocities was Jorge de León, a former personal assistant to one of the leaders and a drug and money trafficker, who was kidnapped after being held responsible for the loss of a marijuana shipment. According to his statement, during his time in prison, he was forced to watch various murders in which the victims were dismembered alive and their remains subsequently incinerated in barrels.

“De León stated that he was forced to witness the murder of a family in their home in Piedras Negras by El Chano, El Enano, and other hitmen. The family consisted of the father, mother, and a girl who appeared to be around six years old. El Chano started with the girl. The body parts that El Chano cut off first were thrown into a fire inside a barrel […] The girl’s mother and father were crying,” the report describes the former Zeta’s testimony.

Jorge de León also witnessed how the mother suffered the same fate as her daughter while El Chano and El Enano forced the father to continue watching until they finally killed him in the same way. This episode was also confirmed by Saúl Fernández, another recruiter, stalker, and firearms smuggler who testified at the San Antonio trial of Marciano Millán Vásquez, known as El Chano.

Members of law enforcement were also targets of Los Zetas’ violence. De León himself recounted the occasion when El Chano, El Enano, El Z40, and El Z42 were present at the murder of three Mexican Army soldiers near a small river on the outskirts of Piedras Negras.

“When I say ‘kill them,’ I mean they were going to dismember them. They were going to cut off their heads and then go after their entire families. And they would do the same to them, regardless of whether they were children or adults,” reads the testimony of the former Zeta member recovered in the report from the University of Texas Law School.

Such incidents led marines and federal police to cover their faces with balaclavas when participating in operations aimed at arresting members of Los Zetas.

In June 2017, Marciano Millán Vásquez (El Chano), one of the Treviño Morales brothers’ main allies in Piedras Negras, was sentenced to seven consecutive life sentences for committing numerous murders and drug and arms trafficking, while his bosses continued to file injunctions to evade extradition to the United States.

In February 2025, both El Z40 and El Z42 were handed over to US authorities to face a trial that is poised to further expose their extensive and painful criminal history, from which Mexico has never recovered.

Source: Milenio