WASHINGTON (CNN) - President Obama and his administration are using references to convicted al Qaeda operative Zacarias Moussaoui as the would be "20th hijacker" as they try to persuade the public the U.S. civilian court system can put on trial and imprison terror detainees.
"Zaccarias (sic) Moussaoui has been identified as the 20th 9/11 hijacker – he was convicted in our courts, and he too is serving a life sentence in prison," the President said in his speech discussing terrorism.
"The 20th 9/11 hijacker was tried in U.S. courts, and is in a U.S. prison right now," said senior White House adviser David Axelrod in an interview on "CNN Newsroom."
But U.S. officials for some time have not believed he was meant to be part of the actual plot.
In the first years after the 9/11 attacks, some officials did call Moussaoui - who was arrested a month before the attacks - the "20th hijacker."
U.S. officials eventually came to focus on a different suspect. They have believed for several years terror detainee Mohammed al-Qahtani was the individual meant to have been the missing hijacker on Flight 93, which had only four on board. In 2004, members of the commission investigating the 9/11 attacks said it was likely al-Qahtani was supposed to be included in the plot, pointing to the fact hijacker Mohammed Atta was at the Orlando, Florida airport in August 2001 when al-Qahtani arrived, as well as other classified information.
But al-Qahtani was prevented from entering the country by immigration officials. Later, he was arrested and sent to the detention facility at Guantanamo Bay, where he was subjected to harsh interrogation techniques that were criticized in internal reports.
Moussaoui himself helped to push the idea when he signed letters to the federal judge overseeing his case as the "20th hijacker" and gave contradictory accounts in court about whether he was supposed to take part in the attacks. In the sentencing phase of his trial, Moussaoui testified he was training to fly in a fifth hijacked plane, but also said he didn't know when the 9/11 attacks were supposed to occur.
Testimony from senior al Qaeda operatives was later introduced saying Moussaoui was not intended to be part of the hijackings and described as mentally unstable.
pleading guilty in June of 2005 to terrorism charges, including being part of the 9/11 conspiracy by lying to investigators about his knowledge of al Qaeda, Moussaoui was sentenced the next year to a life sentence.