On September 10, the FBI and the U.S. Department of Homeland Security confirmed that the AQAP was not involved in the September 3 crash. On November 21, AQAP provided a detailed account of the plot, including photos of the printer bombs, in its English-language magazine "Inspire". The article said that the mission was a success, because it caused a huge amount of disruption to the world's air traffic and security systems at the very low cost of $4,200. "The Guardian" reported that unnamed U.S. counter-terrorism officials suspected that Anwar al-Awlaki of AQAP was behind the plot. "Anybody associated with al-Qaeda in the Arabian Peninsula is a subject of concern," Brennan said. "The New York Times" reported that "some analysts believe the [attempted Chicago bombing] may also be linked to Mr. Awlaki". "The Daily Telegraph" reported that "U.S. and British security officials believe" al-Awlaki was behind the attack. U.S. Ambassador to Yemen Gerald Feierstein said "al-Awlaki was behind the two ... bombs." Al-Awlaki had also been linked to the 2009 Fort Hood shooting, the failed 2009 Christmas Day bombing, the failed 2010 Times Square car bombing attempt, and other terrorist incidents, and had been placed by U.S. President Barack Obama on a targeted killing list. The American Civil Liberties Union and the Center for Constitutional Rights sued in an attempt to prevent his death. Al-Awlaki was killed in a targeted killing in September 2011. US officials suggested that Ibrahim Hassan al-Asiri, the main explosives expert for Al-Qaeda in the Arabian Peninsula, likely built the bombs. He has a history of creating explosive devices using PETN. Brennan said that the evidence pointed to the bombs having been built by the same person who made the device worn by Umar Farouk Abdulmutallab, who attempted to detonate a bomb on a plane on Christmas Day 2009. One of the detonators was almost identical to the one used in that attack. Al-Asiri had previously recruited his younger brother Abdullah as a suicide bomber, hiding a PETN bomb in his rectum in an attempt on the life of security chief Mohammed bin Nayef. Abdullah died in the attempt, but Nayef survived with minor injuries. On October 30, 2010, a 22-year-old female Yemeni engineering student was arrested in Sana'a, Yemen, on suspicion of having shipped the packages.