He was summoned to testify on two occasions before the Supreme Court, who investigated whether Ternera had issued the order for ETA to attack the quarters of the Civil Guard of Zaragoza in 1987, an attack in which eleven people died, among them five children.
Foi citado a declarar en dúas ocasións ante o Supremo quen investigou se deu a orde de cometer o atentado contra a casa cuartel da Garda Civil de Zaragoza en 1987, no que morreron once persoas, entre elas cinco nenos.