That version, delivered by Jesús Murillo Karam, then the attorney general, said the students had been incinerated at a garbage dump after being abducted by local police officers working in concert with the Guerreros Unidos drug cartel. However, this past September, the international experts released a report saying that witnesses reported having seen federal police officials and military personnel at the site of the abduction. Their investigation also ruled out that there had been a fire large enough to burn 43 bodies at the garbage dump.

Instead of acknowledging the significance of those findings, the Mexican government stonewalled requests for information and access to key witnesses. When disparaging articles about two of the investigators — Claudia Paz y Paz, the former attorney general of Guatemala, and Ángela Buitrago, a former Colombian prosecutor — appeared in the Mexican press, the team reasonably interpreted them as a smear campaign carried out with the blessing of a government whose credibility they had undermined.

The team’s second and final report, which was released Sunday, does not conclusively establish what happened to the students. But it’s impossible not to interpret it as an indictment of Mexico’s notoriously corrupt and often brutal justice system. The report, for instance, says the government’s version of events was based on the accounts of witnesses who were tortured. It faults Mexican investigators for failing to explore leads and for refusing to amend prior findings in the face of new evidence. The government’s conduct fueled widespread speculation that federal officials played a role in the crime and later sought to cover their tracks.

The experts outlined their findings during a news conference on Sunday in Mexico City before leaving the country. Their mandate to investigate is expiring and the government has said it will not renew it. Relatives of the victims in attendance chanted “Don’t leave! Don’t leave!” No Mexican officials bothered to show up. That spoke volumes about the government’s lack of political will to reform judicial institutions and its callousness toward its citizens.