Abdelkader Farssaoui, a.k.a. Cartagena, served as a government informant from late 2001 to June 2003, informing on a group of the Madrid train bombers (see September 2002-October 2003). He continued to work with Spanish authorities, and in July 2004, several months after the Madrid train bombings, he hears about a new Spanish bomb plot. He tells authorities that the plot is being led by a man named Mohamed Achraf, who is leading the effort despite being held in a prison in Switzterland on immigration violations. Achraf’s plan is to blow up the National Justice Building (Audiencia Nacional) in Madrid, using 500 kilos (1,100 lbs) of explosives. He is leading a criminal network and has been raising the money for the explosives through robbery and drug trafficking. He hopes that the bomb will kill judges Baltasar Garzon and Juan del Olmo, who are in charge of investigations against suspected al-Qaeda figures in Spain. He also hopes the destruction of the building will destroy many documents about Islamist militants in Spain. [El Mundo (Madrid), 10/21/2004] Beginning on October 18, 2004, Spain arrests about 30 people who they accuse of involvement in the plot. Achraf will be extradited to Spain to stand trial with the others there. As of early 2008, no verdicts have been reached. [BBC, 10/22/2004; BBC, 10/15/2007]