Mexican authorities have handed over to the Medical Forensic Service of the city of Iguala a yet-to-be disclosed number of corpses from a garbage dump near the city of Cocula. Forensic teams from Mexico and Argentina are investigating whether the remains are those of 43 rural teaching students who were forcibly disappeared by the police forces of Iguala and Cocula, acting in collusion with the Guerreros Unidos (GU) drug trafficking gang.

It is alleged that two GU gang members confessed to having been involved and gave federal investigators the information about the Cocula dump. Access has been tightly controlled to the area by security forces. The Mexico City daily La Jornada reported on an incident in which armed men, in a car with no plates, detained a television crew, attempted to smash their way into its vehicle and, failing to do so, motioned for the federal police to block the reporters’ way.

On Tuesday, the Legislative National Security Commission called on the national defense secretary,

General Salvador Cienfuegos, to clear up what the Army’s role was in the massacre and abduction of the Ayotzinapa student teachers on September 26. Alejandro Encinas, president of the commission, promised that the meeting with the general would be “very private.”

According to Encinas, the commission trusts that the Army chief would share intelligence data. Encinas’s promise of privacy and his deferential attitude to the Defense Ministry strongly suggests that the Mexican Congress is seeking to help cover up the Army’s role that night. This is consistent with a government that at all levels acts as if it is under siege.

The commission has also met with Government Secretary Miguel Ángel Osorio and with Attorney General Jesus Murillo, but had avoided until now bringing in the Army itself, as if it had had nothing to do with the Iguala massacre. Given the links between narcotics syndicates and not only the municipal, state and national governments, but the Army itself, this proven untenable.

In particular, the commission wants to know what the 27th Infantry battalion, based less than one mile away from the scene of the massacre, did that night.

The 27th was one of several battalions of soldiers and marines deployed to Iguala and other places during the first years of the war on drugs against drug cartels and guerrilla groups, based on the belief that municipal and state police forces were infiltrated by the drug cartels. However, the activities of the battalion have not been made clear and seem inexplicable

Those normalistas that managed to escape alive from the ordeal, initially said that they suspected that some of the disappeared students were being held in an Army base in Iguala (that of the 27th Infantry). The role of the battalion has never been fully explained. Omar García, one of the surviving students, had described how, after an initial attack by the Iguala police at 9:30 p.m. on September 26 that resulted in the execution of Aldo Gutirrez, a student, the police then withdrew. Four hours later, at 1:30 a.m. on September 27, a second attack was launched on the students, this time by men dressed as civilians and in unmarked cars; more than 200 rounds were fired. Two other students and three bystanders were killed, several students were left wounded and 43 others were abducted.

Students went knocking on doors for help for their wounded comrades and met up with a military patrol that arrived within minutes of the second attack. After stealing their cell phones, the soldiers threatened to arrest them for trespassing. “You guys wanted to be big shots, now pull up your pants!” said the soldiers as they were leaving, according to García.

When informed of the wounded students, the officer in charge offered to call an ambulance (that never showed up). When on Sunday, October 28, relatives of the missing students accompanied by human rights activists questioned Colonel Rodriguez at the Army base, he denied having any of the students in custody. He did admit that the Army had been aware of the attack on the students, and that troops had been sent out to the scene, but that the Army had not participated in the attack.

A report in the Guerrero daily newspaper El Diario de Guerrero the day after the massacre applauded the bloody act of repression against “vandals trying to steal buses,” which it attributed to State Police and the Army itself.

Meanwhile, an embattled President Enrique Peña Nieto has declared his intention to meet with family members of the disappeared students, this fully one month after the massacre and kidnapping. The president is facing mistrust and criticism. The resignation of Guerrero governor Angel Aguirre, one of Peña Nieto’s closest allies in a state that the president had visited more than two dozen times since 2012 (the president has yet to set foot in Guerrero since the massacre), has not helped matters.

The role of the Army in Iguala now places a question mark over how much the federal government knew about the Iguala and Colusa drug connections, when the news of the police assault reached federal authorities, and how involved the Peña Nieto administration was in planning and executing the attacks of that night.