A video showing two soldiers and a federal police agent partially suffocating a woman with a plastic bag has strengthened long-standing allegations that Mexican security forces systematically violate human rights.
The video, uploaded on YouTube earlier this week, shows a young woman being constantly abused as she sits crying on a dirt floor, with her hands tied behind her back.
It begins when her head is covered by a shirt and one of the soldiers, a woman, is yelling questions about a person named María. Moments later, the federal police officer, who is also a woman, rolls a plastic bag over the detainee's head and threatens her with electric shocks or waterboarding. At one point the female soldier points a gun to her head, asking "do you remember now?"
Media coverage of the video, which has since been removed from YouTube, led the army to release a statement on Thursday saying that the event occurred in February 2015 but that the military authorities only learned about it nearly a year later. The statement said that the two soldiers involved — a military police officer and a captain — were arrested soon after that and are currently in custody, within military jurisdiction, charged with "disobedience."
The statement also said it passed the information about the interrogation to the civilian authorities. Torture and other human rights abuses committed by soldiers must, by law, be tried in civilian courts.
The attorney general's office then also revealed that in January it had opened an investigation into the abuses on display in the video within its newly-created Special Investigative Unit on the Crime of Torture.
"In this, as in all cases, the attorney general's office will act with all the rigor that the law allows in order to avoid any impunity for any illicit act."
The statement stands in sharp contrast to the US State Department's appraisal of Mexico within its annual global report on human rights released on Thursday.
The report said that the problem of torture is spreading across the country, and is not restricted to isolated incidents. It also highlighted the "extremely low" rates of prosecution for all forms of crime and abuse.
"The most significant human rights-related problems included law enforcement and military involvement in serious abuses, such as unlawful killings, torture, and disappearances," the report said.
The government of president Enrique Peña Nieto has repeatedly and fiercely denied multiple reports from national and international human rights groups and institutions highlighting the frequency of torture and other forms of abuse. This, some activists say, gives the new video particular importance.
"For many years we have had testimony and documentary evidence of torture which is why we say that the practice is generalized," said Santiago Aguirre, a lawyer from the Centro Pro human rights group. "But to have an audiovisual documentation is exceptional."
Crime analyst and expert in military matters, Raúl BenÍtez, said he did not think that torture is as widespread in the army and federal forces as many activists claim.
"But there is no control in some parts of the country and if the abuses are not made evident, they are tolerated," he said. "Impunity, which is a general problem, means that the sense grows within civil society that something is wrong in law enforcement institutions."
As well as raising the issue of the use of torture, the video also highlights the military's questionable role in Mexico's drug wars. The army was given the lead in the crackdown on organized crime launched by President Felipe Calderón nearly a decade ago, on the grounds that it is more trustworthy than the notoriously corrupt police.
Human rights groups charge that the army's involvement inevitably leads to serious human rights abuses because soldiers are trained to defeat enemies, not to detain criminals while respecting their constitutional rights.
The woman being tortured in the video was later revealed to be 21-year-old Elvira Santibañez, an alleged member ofthe Familia Michoacana drug cartel.
Local media cited anonymous Mexican officials saying that her interrogation took place after she was arrested carrying assault rifles and drugs.
After being tortured, Santibañez was taken to the city of Iguala, and then locked in a federal prison in the western state of Nayarit. Iguala is the same place where 43 students from the Ayotzinapa teachers' school were disappeared in 2014 after being kidnaped by municipal police officers.
The furor triggered by the disappearance of the students in September of that year led President Peña Nieto to promise a 10-point package of reforms to deal with the security crisis. One of these was legislation to actively combat instances of torture.
The deadline for legislative approval for a torture law was subsequently set for January, but the torture bill is currently stuck in a Senate committee.
"This says something about political priorities," said Aguirre, of the Centro Pro human rights group.
Follow Alan Hernández on Twitter: @alanpasten