Mexico agreed on Tuesday to relaunch its investigation of last year's disappearance of 43 teachers' college students, a probe that has been roundly criticized by relatives of the missing and independent investigators.
The country is accepting recommendations by the Inter-American Commission on Human Rights, but will not allow a group of independent experts to directly question military troops about the case.
Eber Betanzos, deputy prosecutor for human rights at Mexico's federal Attorney General's Office, said his entity "completely" accepts a report by the five experts.
One of those experts, Angela Buitrago, a Colombian, said the relaunched search will be carried out "with a strategy based on lines laid out by the group, including the use of technology, mapping of clandestine graves and other locations and establishing a path of action agreed upon by the families."
The students disappeared in September 2014 after being detained by police in the city of Iguala in the southern state of Guerrero, an incident that has generated large protests in the months since.
Prosecutors say the students were handed over to a drug gang, killed and incinerated at a trash dump, though the victims' relatives and independent observers have cast doubt on the official version and criticized what they call missteps and holes in the investigation.
They have called for members of the army, which was in the area when the disappearances took place, to be made available for interrogation, but Defense Secretary Gen. Salvador Cienfuegos has declined to make troops available to anyone other than government prosecutors.
Roberto Campa Cifrian, deputy secretary for human rights at Mexico's Interior Department, said at a hearing in Washington that the experts can get such information through the government but will not be able to confront possible military witnesses.
Buitrago said after the hearing that her group still hopes to question troops because they consider it a crucial piece of the investigation.
"It's not the same to have a third party asking questions," Buitrago said. "Something is going to be missing, or doubt will remain about why something else was not asked."
The experts designated by the commission have rejected a number of the investigation's findings. For example, they say it was not possible for the bodies to have been burned at the dump as prosecutors claim.
They have recommended replacing the team of investigators and exploring other lines of investigation, such as the hypothesis that the students disappeared because they unwittingly hijacked a bus carrying heroin or drug money.
Students at the teachers' college regularly commandeer buses for transport to protests.
The agreement with the government stipulates that Betanzos' office will take over the investigation exclusively, replacing a Prosecutor's Office entity specializing in organized crime, and coordinate with the experts to conduct a new study on the fire at the dump.