The testimony of a captured member of the Zetas organization seems to have resolved the mystery of why that group decided to pull dozens of people off intermunicipal buses Tamaulipas, north Mexico, earlier this year — then torture, murder, and bury them in mass graves.

The Zeta member, Edgar Huerta Montiel, alias “El Wache,” told authorities (see video below) that his group targeted the buses because they feared their rivals, the Gulf Cartel, were getting reinforcements from other states.

“They were orders from above, from [Zetas’ maximum commander Heriberto] Lazcano [that] because those guys were going to the enemy … we had to get them off and investigate them,” he explained.

“Every day a bus came,” he continued, “And the ones who had nothing to do with it were freed. But those that did, they were killed.”

So far, 193 bodies have been found in more than 40 mass graves in Tamaulipas. The murders are blamed on the Zetas, the former armed wing of the Gulf Cartel. The two split definitively in 2010, after Gulf members killed a Zeta commander, then refused turn over the commander’s murderers.

The violent spasm that followed has engulfed two states: Tamaulipas and Nuevo Leon. There, the groups — which both owe much of their development and fortitude to the numerous current and former Mexican security forces personnel on their payroll — have waged a military-style fight, including the implementation of so-called “narco-tanks” (mostly refurbished dump trucks) to move large contingents of troops to battle zones.

mexico_sanfernando_zetasgulfThe Gulf Cartel’s stronghold (as shown in green in the map on the left) is along the northern border from Matamoros through Reynosa to the southern edge of Nuevo Laredo. In its fight against its former protege, it has teamed with the Familia Michoacana and the Sinaloa Cartel.

The Zetas, the core of which are former Mexican Special Forces, have responded by using their stronghold to the south (marked in red) and trying to cut off the Gulf’s supply lines, which includes the municipality of San Fernando (next to the orange marker), a large, grassy flatland. Once known for drawing hunters from Texas, San Fernando has now become Mexico’s killing field.

How did you know if they were part of the rival group, the official interrogating Huerta asks.

“The places they came from; the telephone, the messages,” the Zeta responds. “There were six buses, more or less.”

Huerta says the Zetas were particularly worried about buses from Michoacan and Durango, from where the Familia and Sinaloa Cartels may have been dispatching the reinforcements.

Huerta’s testimony coincides with others. He says, for example, that he gave orders to Martin Omar Estrada Luna, alias “El Kilo,” a former gang leader who spent part of his formative years in Washington state accumulating a criminal record but seems to have graduated to new level of terror once descending into Mexico.

Estrada was arrested in April, and Mexican intelligence officials told InSight that he took orders from Alejandro Treviño Morales, alias “Z-42,” the brother of the organization’s other top commander Miguel Treviño Morales, alias “Z-40.”

The other commander in this equation, Salvador Alfonso Martínez Escobedo, alias “La Ardilla,” who Huerta says was his direct boss and who Mexican authorities say is the head of the Zetas in Tamaulipas, remains at large.

Huerta’s testimony appears credible, logical and seems to resolve the key question surrounding the mass murders that were going on earlier this year: Who targeted the buses and why.

Steven Dudley is the co-founder and co-director of InSight Crime and a senior research fellow at American University’s Center for Latin American and Latino Studies in Washington, DC. In 2020, Dudley...