The body of José María Martínez Cubero was found on 21 September 1984 by the tenant of a farmhouse in the municipality of San Salvador del Valle. His hands and feet had been bound with duct tape and he had been shot in the back of the head. He had died instantly.
The businessman had been kidnapped by ETA and driven to the vicinity of an abandoned mine in his own Dyane 6 car. There, on the road leading to the old mining works, the terrorists murdered him in cold blood, abandoning the vehicle a short distance away. The following day, a caller purporting to speak on behalf of the terrorist group claimed responsibility for the crime and gave indications of the location of the body. By then the victim had already been found, although his death was not initially attributed to ETA.
José María, aged forty-one, was a native of León. He was married and had two children. He bought and sold gold and electronic devices in the town of Portugalete, where he had been living for some years.