Juan Nepomuceno Bastías Bustos died that day at 7:45 hours, at the Seventh Precinct of Carabineros, due to a gunshot wound to the cranium, as recorded in the Medical Death Certificate from the Legal Medical Institute.

An Administrative Summary Investigation was initiated regarding the death of Juan Bastías, which established that he was found dead inside the Contract Personnel Casino, on the second floor of the police unit where he served, the Seventh Precinct of Carabineros, with a gunshot wound behind his right ear.

In the ruling by the investigating prosecutor of that inquiry, dated February 1, 1974, it was concluded that Juan Bastías had committed suicide around 6:30 hours on the indicated day using his service revolver.

One of the considerations in this ruling stated: "That it has been reliably proven that the aforementioned Carabineros officer Bastías was an overly introverted person, recently affected by an acute neurosis caused by nervous-type stomach ulcers and, also, affected by the events that occurred on September 11 last, it being presumed that this led him to make the decision to commit suicide." (sic).

Based on the evidence gathered, the Superior Council reached the conviction that Juan Nepomuceno Bastías Bustos's decision to end his life was adopted in a psychological state provoked by the prevailing situation of political violence, and, consequently, declared him a victim thereof.