Hernán Horacio Castillo Calcagni died that day at 10:15 hours, at Calle San Martín Nº 50, Santiago, due to a gunshot wound to the cranium, as recorded in the Medical Death Certificate from the Legal Medical Institute.

According to information provided by witnesses, Hernán Castillo, an employee of the Compañía de Teléfonos de Chile (CTC), was struck by the bullet while he was at the company's management offices, on the fifth floor of a building located in the vicinity of the La Moneda Palace.

According to the witnesses' account, intense gunfire was occurring near this location and throughout the center of the capital.

The Superior Council, despite not having been able to determine the exact circumstances of his death, considering the cause of death and the time and place in which it occurred, reached the conviction that Hernán Horacio Castillo Calcagni was a victim of the prevailing political violence.