[2] Muguruza was a member of the Herri Batasuna and was part of the moderate group within the party who supported the peace talks between the Government of Spain and ETA.

[6] Ricardo Sáenz Ynestrillas, a member of the neo-fascist group, Spanish Social Movement (Movimiento Social Espanol), was arrested and tried for his alleged involvement in the killing of Muguruza, but soon released due to the lack of evidence.

[8] Later seven individuals, including a former police officer, Ángel Duce Hernández, were arrested in late July 1990.

[11] Duce confessed in the trial that he and two other men murdered Muguruza for political reasons, but claimed that Ynestrillas was not involved in the attack.

[9] Duce was killed in a traffic accident in Alcorcón in August 1997 while he was using a six-day prison permit.