The initial complaints calling for the Judiciary to investigate clandestine repression were filed by the victims and their families during the dictatorship. Hundreds of Habeas Corpus petitions were submitted in response to the disappearance of persons, although they did not accomplish the expected outcome at the time. Nevertheless, they were later recognized as pivotal to prove the facts.

In a few exceptional cases, these early filings led to the opening of an investigation. Despite the fact, it failed to determine criminal accountability at the time, it paved the way for the gathering of evidence and the reconstruction of the truth.

On August 2, 1978, Paulino Guarido appeared before the National Lower Court on Criminal Matters No. 3, presided over by Honorable Carlos Oliveri. He reported that he had been held captive along with his wife, Mónica Piñeiro. Guarido, a 22-year-old militant of Vanguardia Comunista, had been arrested in July together with a large group of militants from that organization. He was unaware of where he had been kidnapped when he testified. This marked the beginning of case number 35,040/78. Subsequently, the case proceeded and the clandestine detention and torture center was located and described. It was the clandestine detention center known as El Vesubio in La Matanza, in the Province of Buenos Aires. The first trial for the crimes committed in this clandestine detention center would not begin until more than thirty years later, in February 2008.