Zacarias Moussaoui

Zacarias Moussaoui (Arabic: زكريا موسوي, Zakariyyā Mūsawī; born 30 May 1968) is a French terrorist who was a member of the al-Qaeda militant organization. He likely planned to participate in the September 11 attacks (9/11) in 2001, in which 19 members of al-Qaeda hijacked four American airliners in an attempt to crash them into U.S. landmarks.

Many of the hijackers went to flight schools in the U.S. in the lead-up to the attacks. In August 2001, while Moussaoui attended one in Minnesota, he aroused suspicion and was arrested by the FBI for violating immigration laws. In December, he was indicted by a federal grand jury on six felony charges relating to the attacks.

Prosecutors alleged Moussaoui was going to be al-Qaeda's "20th hijacker", after Ramzi bin al-Shibh and Zakariya Essabar were denied visas to enter the US. Legal analysts viewed his trial as a barometer of America's ability to give a fair hearing to terrorism suspects after 9/11. Moussaoui argued he was not involved in the attacks, but instead had been planning a similar attack of his own. Some al-Qaeda members reportedly corroborated his defense, but prosecutors believed it had no merit.

In May 2006, Moussaoui was sentenced to life in prison without the possibility of parole. The jurors voted against him receiving the death penalty, citing his unstable childhood and possible ignorance of al-Qaeda's plans. He is currently held at the ADX Florence federal supermax prison in Colorado, and remains the only person ever convicted in an American civilian court of a crime in connection with 9/11.