The National Commission on the Disappearance of Persons (Comisión Nacional sobre la Desaparición de Personas, CONADEP) was created by Raúl Alfonsín on December 15, 1983. Its mission was to investigate what had happened during the dictatorship. The commission was made by leading figures from the cultural, scientific, religious, and journalistic sectors, human rights advocates, and policymakers under the leadership of writer Ernesto Sábato.

Human rights organizations provided all the information they had collected, and CONADEP traveled all over the country to compile testimonies and visit the places where repression had actually occurred. This is how it gathered accounts from victims and their families about abductions and disappearances. It also compiled testimonies from members of the Armed Forces and security personnel and succeeded in locating hundreds of places that had been used as clandestine detention centers. In September 1984, CONADEP presented its report Nunca Más (Never Again). This document revealed the mechanisms of repression, the primary targets and their characteristics. It disclosed over eight thousand disappearances, the existence of clandestine detention centers, the torture inflicted upon those who had been abducted; the misappropriation of children and the theft of property. Nunca Más was to become a foundational instrument for the subsequent trials addressing crimes against humanity.