Mexico said on Monday it has arrested the former head of a federal anti-kidnapping unit in connection with the disappearance of 43 students in 2014. Gualberto Ramírez was head of the anti-kidnapping unit for the attorney general’s office when the students from the Ayotzinapa teachers college in southern Mexico went missing.

Assistant Interior Secretary Alejandro Encinas wrote that Ramírez faces charges of disappearance, torture and conspiracy for the botched investigation into the abductions, which are defined as “disappearances” under Mexican law because only remains of three of the victims have been identified.