The UN Office of the High Commissioner for Human Rights (OHCHR) released a report [executive summary, PDF] on Thursday detailing human rights violations that occurred during the early parts of the investigation into the kidnapping of 43 students from Ayotzinapa [BBC backgrounder] in Mexico.

The OHCHR’s report covers human rights violations from September 2014 to January 2016 committed by the Mexican government during the investigation. The report is based on accounts from 63 of the 129 people who were prosecuted in the aftermath of the tragedy. The OHCHR’s report assessed 51 cases filed against people convicted of involvement in the kidnapping and found strong evidence of torture and arbitrary detention in 34 of those cases.

In the 34 cases, the report states there was “an almost uniform modus operandi” including “arbitrary detention of suspects,” and “acts of torture occurring mostly in the first 48 hours following the arrest, with the intention of extracting information or a confession.” In addition, “[s]ome of the self-incriminating statements obtained under torture were used as the basis for the accusation against the detainees, as well as in indictments against other individuals.”

The officials involved in this process include staff of the OAG (Office of the Attorney General of the Republic) – mainly from SEIDO ( Special Investigations on Organized Crime) the Criminal Investigation Agency – as well as personnel of the Federal Police and the Mexican Navy.

All of the documented human rights violations in the report occurred after 5 October 2014,” after the OAG took over the investigation from the Office of the Attorney General of the State of Guerrero.” Currently, 33 of the 34 individuals reported in the case are still currently in detention.