Aranzazu Berradre Marín was the pseudonym under which a national policewoman infiltrated terrorist group ETA. When she was only 20, the young woman managed to enter the gang by presenting herself as a militant of the Movement of Conscientious Objection of Logroño, being the only woman who lived in an apartment with ETA leaders. During her infiltration, she made possible the dismantling of the Donosti commando at a crucial moment when the gang was falsely declaring a truce.