Police agents in San Fernando in the northeastern Mexican state of Tamaulipas aided Los Zetas drug gang in carrying out massacres of hundreds of Central American migrants and others in 2010 and 2011, according to a partially redacted document declassified by Mexico's Attorney General's Office (PGR). Although collusion between local Tamaulipas police and criminal gangs was already well known—US diplomatic cables released by the US government in 2013 discussed it, and locals refer to the police as "polizetas"—this is first time that the PGR has been required to release a document from an ongoing criminal investigation. Previously federal prosecutors had insisted that Mexican freedom of information laws didn't apply to open investigations. The document is now available on the website of the Washington DC-based National Security Archive, along with other relevant documents, including reports from US government agencies and US diplomatic cables released by the WikiLeaks group.

The undated PGR document is based on testimony from some of the 17 San Fernando police agents who were detained in connection with mass killings in the area; the most famous, often called the San Fernando massacre, involved the discovery of 72 bodies of migrants in a mass grave in August 2010. "I know that police and transit officials in San Fernando help the Zetas organization," Alvaro Alba Terrazas, one of the detainees, told investigators, "because rather than take detainees to the 'pentagon,' which is to say the municipal jail, they would deliver them to the Zetas."

Michael Evans, the director of the National Security Archive's Mexico Migration Project, noted the similarity to the Sept. 26-27 abduction of 43 students from Raúl Isidro Burgos Rural Teachers' College, located in Ayotzinapa in the southwestern state of Guerrero. According to federal investigators, the Iguala municipal police detained the students and then turned them over to a local drug gang. "If all this sounds eerily familiar," Evans told the Mexican newsweekly Proceso, "it's because we've seen it before. Murders like this are disturbingly common in Mexico, and the forces behind the chaos—generally drug cartels counting on the collaboration of, at a minimum, the local police—have been remarkably consistent over time."

Evans and another National Security Archive analyst, Jesse Franzblau, noted that the document raises a number of questions: why it lists 17 detainees when the media reported 16 at the time of their arrests, why two of the detained agents are described in later media reports as actual members of the Zetas, whether the detainees are still detained, and where they are now. (Expresión Libre, Cancún, Dec. 21; National Security Archive, Dec. 22)

From Weekly News Update on the Americas, December 28.