Juan Santos Jaque Arellano died that day at the Posta Central from abdominal gunshot wounds, as recorded in the Medical Death Certificate from the Legal Medical Institute.

According to witness accounts, on September 19, 1973, at approximately 16:00 hours, Juan Jaque was watching television with a group of friends at a neighbor's home in the Isabel Riquelme neighborhood, in the commune of San Miguel (currently the commune of San Joaquín), when they were warned of the presence of military personnel in the neighborhood conducting a military operation.

Upon learning this, the young men fled the scene quickly, and in the attempt, the military personnel fired upon them. Several were wounded by the gunfire. Among them was Juan Jaque, who was transported to the aforementioned medical center, where he died days later.

Gilberto Matamala Venegas and Humberto Picarte Patiño were also wounded by the gunfire and subsequently died; their cases were reviewed by the National Commission for Truth and Reconciliation, which declared them victims of human rights violations.

Considering the evidence gathered and the investigation conducted by this Corporation, the Superior Council, noting that there were, without a doubt, less violent means to detain a minor who was fleeing from the actions of State agents along with other minors, reached the conviction that Juan Santos Jaque Arellano was killed by the irrational use of force by State agents.

For this reason, it declared him a victim of human rights violations.