The families of the victims in one of Mexico's most infamous atrocities say it's time for the government of President Claudia Sheinbaum to release all of the information it holds about the role the military played in the disappearance of 43 students from a teachers' college in Ayotzinapa, Guerrero.

Thousands marched along one of Mexico City's main thoroughfares on Saturday to the National Palace, in the capital’s historic centre, to mark the 12th anniversary of the students’ disappearance from the all-male school.

"Everything points to the military," said Maria de Jesus Tlatempa, the mother of José Eduardo Bartolo Tlatempa, one of the 43, who was 19 years old when he vanished.

Tlatempa and the other fathers, mothers, uncles and siblings of the 43 led the march, which began in the shadow of Mexico City’s iconic Angel of Independence monument, ringed on Saturday by steel fencing.

The families say that the passage of time and subsequent — sometimes conflicting — investigations have failed to answer fundamental questions about what happened to the students, why and where they were ultimately taken and what role federal institutions like the military played in the tragic event.

"Up to this day, we don't really know what happened to our sons," Tlatempa said.

Sheinbaum announced on Friday that her government would be issuing an update on the progress of the ongoing investigation into the disappearances on Monday.

Her administration arrested the former governor of the state of Guerrero in August and charged him with obstruction of justice and forced disappearances. Mexican authorities are also seeking the extradition of two suspects from the United States, including a former judge who obtained political asylum.

43 Mexican students went missing 12 years ago. Their families want answers 11 hours ago Duration Unravelling 'historical truth' On Sept. 26, 2014, the students from the Raúl Isidro Burgos Rural Teacher-Training College in Ayotzinapa were in Iguala, Guerrero, to commandeer buses for a rally in Mexico City and take part in a demonstration commemorating the 1968 massacre of university students.

They never arrived. Municipal police officers allegedly attacked the buses, leading to a chaotic night that ended with six deaths — including those of three students — and the disappearance of the 43.

"We are here to demand the return of our 43 comrades alive," Rodrigo, a masked 22-year-old student from the Ayotzinapa college, told CBC News at the protest, adding he would give only his first name due to fear of being targeted by state security forces. "Ayotzinapa won't stop or rest until we find our 43 disappeared comrades." Mexico's top court orders release of 43 missing Ayotzinapa students case file The administration of Enrique Peña Nieto, who served as president until 2018, initially claimed in its "historical truth" about the events in Iguala that the 43 students had been attacked, taken by municipal police and handed over to a local organized crime group called Guerreros Unidos.

Then-attorney general Jesús Murillo Karam and Tomás Zerón, former head of the criminal investigations agency, claimed the bodies of the students were burned for 14 hours on a pyre at a garbage dump in the municipality of Cocula, which sits about 20 kilometres southwest of Iguala.

Karam, arrested in 2022, is currently under house arrest while facing charges of forced disappearance, torture and obstruction of justice in connection with the handling of the case. Zerón is currently a wanted fugitive reportedly living in Israel.

The term "historical truth" in Mexico is generally used to describe a theory crafted by government players, law enforcement and politicians, often amplified by the media, that becomes the dominant version of a major event.

However, independent international experts disproved the dump cremation theory as scientifically impossible, and a 2018 federal court ruling found that the confessions used by Karam and Zerón to construct their theory were obtained by torture, said lawyer Isidoro Vicario, who represents the families of the 43 missing students. "The information that was offered has no credibility," he said.

Mexican officials make 1st high-level arrest in notorious 2014 disappearance of 43 students The DNA of three students has so far been matched with remains found in two locations — one found in a river roughly 10 to 12 kilometres downstream from the dump and the two others found in a ravine about 800 metres from the dump.

In March, a Mexican federal court ruled the military needed to release more than 853 pages of information created by its internal intelligence agency that were related to the case. The military had initially denied the existence of the documents. "To this date [the military] has not complied," Vicario said.

"That's also part of what upsets the mothers and fathers." Expert report connects military to events A group of experts — created in November 2014 under an agreement between Peña Nieto's government, the Inter-American Commission on Human Rights and the families — released a report in 2022 that found the military's fingerprints all over the events of Sept. 26, 2014, and in the construction of the discredited theory initially presented by the federal government.

The report, by the Interdisciplinary Group of Independent Experts, found that the Mexican military had both the Ayotzinapa students and the Guerreros Unidos under surveillance.

It also said the military had infiltrated the teachers' college for about a decade and knew the Guerreros Unidos moved heroin to the U.S. using the same types of passenger buses the students had commandeered.

Mothers crossing the Mexico-U.S. border risk everything to reunite with their children Family wants killing of young engineer linked with case of kidnapped Canadian mining firm workers The report found the local military battalion had real-time surveillance — through cameras and wiretaps — of the violence that unfolded that night in Iguala and that military assets were also stationed near the scene of the conflict.

The report alleged the military was involved in the tortured confessions and that its personnel were also present at the Cocula dump before it was presented as a cremation site.

Mexico’s National Human Rights Commission released a report in July that was widely interpreted as absolving the military of responsibility in the events.

Mediante la 208VG/2026, acreditamos violaciones graves a los derechos humanos de 92 estudiantes de la Escuela Normal Rural “Raúl Isidro Burgos” de Ayotzinapa, así como deficiencias en las investigaciones relacionadas con los hechos ocurridos en Iguala, Guerrero, en…CNDH The families of the 43 met with Supreme Court Chief Justice Hugo Aguilar Ortiz on Friday and discussed the military’s continued non-compliance with the March federal court order to release documents.

"He said he would be reviewing that order that the military provide that information," said Meliton Ortega, whose nephew, Mauricio Ortega Valerio, was 18 when he vanished.

"That information is not going to go directly into the hands of the parents but to the institutions that are still handling the case."

Vicario, the families' lawyer, said the parents also raised the recent referral of the 2018 federal court ruling by Sheinbaum's office to the Supreme Court for review. That decision — which found the Peña Nieto government used torture to obtain confessions — was initially criticized for judicial overreach.

The 2018 ruling called for the creation of a commission of investigation to look into the Ayotzinapa case composed of the head of the National Human Rights Commission, representatives of the parents and the federal attorney general’s office, Vicario said.

"That ruling helped toss the theory of the garbage dump in Cocula. But if the Supreme Court reverses that ruling ... it's a serious problem. It's definitely very risky for the Ayotzinapa case," he said. 'We have to find them'

Time is also an enemy of the families of the 43 young men in their years-long quest for answers. Many of the parents are ailing, and some have died without ever knowing the fate of their sons.

Lourdes Caballero Sanchez's brother, Israel Caballero Sanchez, was 21 when he vanished on the night of Sept. 26, leaving behind an infant daughter. She said their father died in August 2014 — a month before the tragedy — and their mother passed away last December. "She left us without knowing about her son," Caballero Sanchez said. "But I told her, 'Mom, I am here.... Israel still has a family.'

His mother, his father are no longer here, but his family still is, and we are going to continue the struggle, for him and for his friends. We have to find them. We have to know where they are, we have to find that truth that we've searched for over the past 12 years."