Parents of 43 students who went missing after they were attacked in southern Mexico by police in September 2014 say they just want to know the truth about their children's fate — something they thought a team of outside experts would help them obtain.
Now those experts are about the leave the country after delivering a devastating final report on the government's investigation, and the families are losing hope that the painful mystery will ever be solved.
"We have only sought the truth and the government has put obstacles in our path," said Emilio Navarrete, whose son José Ángel studied at the Ayotzinapa teacher training college. His son is among the 42 students who are still missing after just one has been identified by a jaw fragment.
"Without the experts, we wouldn't know the lies that the government has been telling us," said another parent, Bernardo Campos.
"From the start, we did not accept the government version and now we have scientific proof that it didn't happen as they said," said Cristina Bautista, another of the parents.
The families of the missing students were talking at a press conference on Monday in which they accused the government of trying to prematurely turn the page on one of the country's most notorious crimes that, 19 months after the events, is still a long way from being solved in a way that satisfies them.
After a year accompanying the government's investigation the experts — who were convened by the Inter-American Commission on Human Rights — are now packing their bags because the government has refused to extend their mandate, which runs out at the end of the month.
Last Sunday they provided an unflattering final report that backs the parents' long-standing claim that the official probe is rife with irregularities, made all the more damning by allegations that the government sought to undercut their investigation and harassed them out of the country.
"The group has suffered a campaign trying to discredit people as a way to question their work," the report said. "Certain sectors are not interested in the truth."
The students from Ayotzinapa were attacked on September 26, 2014, in the southern city of Iguala, where they had gone to commandeer buses in which to travel to a protest in the capital a week later.
The horror of the Iguala attacks and the disappearance of 43 students, together with the government's slow response and accusations of investigatory incompetence, sent President Enrique Peña Nieto's popularity plummeting, while staining Mexico's international image.
The government's invitation to the expert panel was seen as an effort to prove it had nothing to hide.
Now their report underlines evidence that a variety of different police forces, potentially including the federal police, coordinated efforts to prevent the buses from leaving Iguala. The army, meanwhile, did nothing to stop the attacks even though they were monitoring them closely.
The experts also found no evidence to sustain government claims that the students' bodies were burned in a garbage dump. They suggested evidence to support this hypothesis was planted by investigators, and alleged the official probe has blocked efforts to explore whether the students were attacked because they had unwittingly taken a bus filled with hidden opium paste.
The government did not send a representative to hear the report, despite the presence of the president of the Inter-American Commission on Human Rights. Instead it brushed off the criticism in a statement which insisted that it welcomed all the experts' contributions, claimed that it had fully cooperated with them at all times, and that the allegations in the final report are unfounded.
The government also promised to continue the probe and to work closely with the families in the future.
"The government and the students' relatives are on the same side and have the same goal," said the statement, that was read by the current head of the investigation, Eber Omar Betanzos. "We want to find out what happened to the students and to punish each and every one of the individuals responsible."
With the departure of the experts, the Inter-American Commission on Human Rights is now due to form a new group to monitor the Iguala investigation.Though the details have yet to be determined it appears clear the government will not allow it to get as close to the official probe as the outgoing experts.
Certainly the parents are not expecting much. Instead of talk of future collaboration with the government, they said they would be seeking prosecution of a top investigator.
"What we want is the truth and for the facts to be made clear," said Nicolás Vargas, whose son Édgar was injured in the attack by police in Iguala. "That for us would be repairing the damage."
Follow David Agren on Twitter: @el_reportero