On 21 January 1973 , along with other members of ETA , he used a powder keg with more than 3,000 kilograms of dynamite and various explosive materials to plan an attack . Part of those explosives were used in December 1973 to kill Luis Carrero Blanco , who served as Spanish Prime Minister during the Franco government . He later assumed responsibility for the military front Eustakio Mendizábal Benito . In January 1989 , he was arrested in Bayonne with Elena Beloki , the leader of Herri Batasuna , who was later recognized as the organizer of the international apparatus of ETA . He was sent to Fresnes Prison near Paris . Later he was extradited to Spain , where he was freed when it was considered that he had been judged in France regarding his membership and financing of ETA and the other crimes of which he had been accused . 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 . On 26 October 1990 , he was found guilty and was sentenced to ten years in prison for conspiracy , use of false documents and illegal possession of weapons
an attack in which eleven people died
1987 Zaragoza Barracks bombing
Josu Urrutikoetxea