On October 20, 1973, three Socialist militants were also victims of political execution:

-Oscar Walter Pedro RIPOLL CODOCEO, 38 years old, metallurgical engineer, official at the Technical Cooperation Service (SERCOTEC).

-Julio Gastón VALENZUELA BASTIAS, 28 years old, radio operator for the Arica-La Paz railway.

-Manuel Francisco DONOSO DAÑOBEITIA, 26 years old, sociologist, professor at the Universidad del Norte.

All of them were detained on October 9, 1973, and taken to the Rancagua Regiment in the city of Arica, where they remained detained and held incommunicado until October 18, the date on which they were transferred to the Investigaciones barracks. From there, they were removed in the early hours of October 20 by military personnel to be transported to Pisagua.

The following morning, the Arica press published a report provided by the Military Command which stated: "A Military Commission traveling toward Pisagua to transport detainees suffered an accident, presumably due to mechanical failure of the vehicle, which caused it to overturn.

The incident occurred 40 kilometers south of Arica, and all occupants perished. The list of the deceased is as follows: Corporal 1st Class Humberto Villalobos López; Private 1st Class José Martínez Albarracín, Oscar Ripoll, Waldo Sankán, Julio Valenzuela, and Manuel Donoso." The following day, also through the press, it was reported that after the rescue operation, "it was established that the detainee Waldo Sankán was not among the dead, having presumably fled the scene, a fact that was confirmed that same afternoon when the detainee Sankán voluntarily presented himself to the military authorities. Through Sankán's statement, it has been determined that the accident was due to mechanical failure, and the driver was unable to prevent the vehicle from falling into a ravine." Although the deaths of these individuals were presented as accidental, the Commission reached a different conviction:

-The detainees in the vehicle, all militants of the Partido Socialista, had been accused in the press of being involved in the "sinister Plan Zeta that was to be executed in Arica by a paramilitary organization of the former Partido Socialista called AGP (Agitation and Propaganda)";

-Based on testimonies that provide this Commission with full conviction, it can affirm that Donoso, Ripoll, Sankán, and Valenzuela were removed from the Investigaciones barracks in Arica in the early hours of October 20, 1973, in a station wagon, blindfolded and with their hands tied.

After traveling forty kilometers to the south, the vehicle stopped; the drivers got out while the civilians remained inside. The former pushed the station wagon until it plunged into a ravine, where the detainees met their deaths, with the exception of Sankán, who miraculously survived;

-Julio Valenzuela was in an agonizing state or perhaps already dead. His death certificate indicates the cause of death as: "Gunshot wound with pulmonary explosion";

-The military personnel mentioned in the news report have no record of death. The Ejército did not include them among the victims declared before this Commission.

This Commission is fully convinced that Oscar Ripoll, Julio Valenzuela, and Manuel Donoso were victims of a grave violation of human rights for which State agents are responsible, having killed them outside of all legal norms.