Terror Watch: Secrets of the 20th Hijacker

Behind a veil of secrecy, the role of a mysterious Saudi national in U.S. military detention at Guantanamo Bay has become a central and hotly contested issue in the case of Zacarias Moussaoui--the French citizen who remains the only defendant charged by the United States with any connection to the September 11 plot.

Moussaoui's court-appointed lawyers, NEWSWEEK has learned, have been trying for more than a year to question the Saudi, identified by federal officials this week as Mohammed al-Qahtani, an Al Qaeda fighter who was picked up by U.S. military troops during the war in Afghanistan two years ago and was then transferred to Guantanamo Bay.

Al-Qahtani is widely seen by some federal investigators as the most likely candidate to have been the the so-called 20th hijacker, the terrorist who was supposed to be on United Flight 93 that crashed in the fields of Pennsylvania on the morning of September 11, 2001. In August 2001, sources say, al-Qahtani flew from London to Orlando, Fla.--but was blocked from entering the United States by an alert federal immigration inspector who was suspicious of al-Qahtani's claim that he was planning to meet a friend upon his arrival.

The case, which was first reported in this week's NEWSWEEK, illustrates how little the Justice Department has publicly revealed about major aspects of the Moussaoui case. Although there has been no public reference to al-Qahtani's existence, Moussoui's lawyers were first informed about him about a year ago under federal rules that require federal prosecutors to share exculpatory information with defense lawyers, sources say. Ever since, the Moussaoui defense team has argued they should be given the opportunity to question al-Qahtani on the grounds that he could disprove government claims that Moussaoui, whom FBI officials once thought was slated to be the 20th hijacker, had any connection to the 9/11 plot at all.

Justice Department lawyers have refused to give defense lawyers access to al-Qahtani--or any other 9/11 figures in U.S. custody, such as Khalid Shaikh Mohammed and Ramzi bin al-Shibh. The matter, including the potential significance of al-Qahtani to the 9/11 plot, has been the subject of more than one closed-door hearing before the Fourth Circuit Court of Appeals. The appellate court is currently reviewing the Justice Department's appeal of a federal judge's order that the case against Mousssaoui be dismissed if defense lawyers are not given the right to question detainees.

The most compelling evidence that al-Qahtani was supposed to be part of the 9/11 plot is the discovery by federal investigators that Mohammed Atta, ringleader of the hijackers, was at the Orlando airport the same day that al-Qahtani was supposed to arrive. The FBI determined that Atta even made one and possibly two overseas calls to a Middle Eastern country from the Orlando airport--apparently because he was concerned that the individual he was supposed to meet had not gotten off the airplane.

Even if Moussaoui's defense lawyers were to get access to al-Qahtani, it is far from clear that they would gain new testimony that would be helpful to their case. U.S. officials have imposed a tight clamp of secrecy about all the prisoners at Guantanamo--refusing even to confirm the identities of any of the more than 600 prisoners there, much less grant them a right to a lawyer. But sources tell NEWSWEEK that al-Qahtani, unlike some other major Al Qaeda figures in custody, has been uncooperative with U.S. interrogators.

Still, a Justice Department spokesman said today that whatever al-Qahtani has to say shouldn't make any difference to the case against Moussaoui. Federal prosecutors have long since abandoned the theory that Moussaoui--who was arrested in Minneapolis in mid-August 2001 after flight-school instructors grew concerned about his curious interest in studying how to fly an airliner without learning how to land or takeoff--was supposed to be the 20th hijacker. Instead, they have argued more amorphously that he was part of a broader and still undefined Al Qaeda conspiracy that included the 9/11 attacks--along with other planned terrorist strikes against U.S. targets.

For all they have learned about the plot, federal investigators are still unsure whether the September 11 conspiracy was designed to include other airline hijackers that day, or "follow-on" attacks that were planned for the days or even weeks after the original strikes. Moussaoui might well have been part of the follow-on plan, said Justice Department spokesman Mark Corallo. " We still don't know the full extent of the plot," he said. Not long after 9/11, some U.S. officials said that there were indications that Al Qaeda had wanted to hijack at least two other planes on or around the same day. But investigators have found details of these plots hard to pin down.

In Europe, authorities did arrest--and subsequently convict--several conspirators, including a former professional soccer player, for allegedly plotting a round of post-9/11 attacks against targets in Europe. According to French police documents examined by NEWSWEEK, these would have included a major attack on a U.S. airbase in Belgium. Another possible target for an air attack or truck bombing, may have been the U.S. Embassy in Paris. Investigators believe the orders for these attacks, like the orders for 9/11, originated with Osama bin Laden.