The case of the missing students has long gripped Mexico. The students, all males at the local Ayotzinapa Rural Teachers’ College, were traveling through the southwestern city of Iguala on September 26, 2014 when their bus was stopped by local police and military forces. Exactly what transpired after that interaction is still unknown, but photos from the scene show a bullet-riddled bus.

A government report from 2022 concluded that the vanished students were victims of “state sponsored crime.” In 2023, a report from the Office of the United Nations High Commissioner for Human Rights in Mexico found that Mexico’s Armed Forces did not provide all the information requested by an independent panel investigating the disappearance. That same year, experts on that panel looking into the case quit, citing “lack of information,” “secrecy” and “hidden evidence” surrounding their investigative efforts.

For grieving families, the arrest reinforces suspicions of a possible cover-up related to the 2014 disappearances. Felipe de la Cruz, one of the Ayotzinapa parents and spokesperson for the group of parents of the disappeared, told CNN on Thursday that a “pact of silence continues to reign” in the area.

“For us, it is very important that first of all, the investigation continues, and that work continues to be done,” de la Cruz added.