Jesús Alcocer was a former army major and had been an active member of the Fuerza Nueva (New Force) far-right political party. He owned three supermarkets. Over a period of at least five years, he had suffered repeated attacks by all the ETA units operating in Pamplona. A bomb had been left in one of his businesses, another device had been placed in his car and on one occasion, ETA members had lain in wait for him at the main door of his home, intending to kill him. However, all previous attempts on his life had failed. On 13 April 1984, two ETA terrorists went to Mercairuña, the central market where Jesús Alcocer bought supplies for his shops. They shot him twice in the back of the neck, killing him instantly.
They made their getaway in a car which they abandoned in Ermitagaña with a bomb inside. When police officers Juan José Visiedo and Tomás Palacín went to examine the vehicle, terrorist Mercedes Galdós, dressed as a nun, detonated the device. Both officers were killed.