The jury in U.S. District Court convicted Ahmed Omar Abu Ali, 24, of Falls Church, Virginia, on all nine counts after 2 1/2 days of deliberation. The charges include conspiracy to assassinate the president, conspiracy to hijack aircraft and providing material support to al Qaeda.
The charges carry a possibility of life in prison and a mandatory minimum sentence of 20 years, prosecutors said. Sentencing is scheduled for Feb. 17.
CBS News correspondent Barry Bagnato reports that the defense argued that a coerced confession in a foreign country should not be the basis for bringing a case against an American citizen in U.S. courts. Eventually, that issue could wind up before the Supreme Court.
Abu Ali's lawyer, Khurrum Wahid, said he will appeal.
Abu Ali "is disappointed that the jury didn't see the truth and he wants us to continue the fight," Wahid said after the verdict.
Wahid said he believes it's difficult for any person to get a fair trial when the accusations involve al Qaeda.
"I think the country went through a very traumatic event on Sept. 11 and it's very difficult for people to separate that from the facts in a particular case," he said.
Jurors in the three-week trial saw a videotaped confession Abu Ali gave to the Saudis in which he said he joined al Qaeda because he hated the United States for its support of Israel. Notes taken by Saudi interrogators showed that he discussed numerous potential terror plots, but the one that most appealed to him was killing "the leader of the infidels" — President Bush.
Defense lawyers argued, though, that Abu Ali gave a false confession after being whipped and beaten by members of the Saudi security force known as the Mubahith.
Juror Nancy Ramsden said the videotaped confession was a "very striking" piece of evidence for her.
"It was very telling. It was almost sort of a joke for him," she said, referring to points in the tape where Abu Ali laughs and pantomimes the use of an assault rifle.
Ramsden said the jurors agreed from the beginning that they did not believe Abu Ali was physically tortured, but some jurors had initial questions about mental torture.
Abu Ali, who testified in detail about his detention and alleged torture at a pretrial hearing, chose not to testify at trial. He instead relied on the testimony of a doctor and a psychiatrist who said Abu Ali's account was consistent with being tortured. He also relied on photographs of his back that were shown to the jury, which depicted faint linear marks that he said were scars left from the flogging.
Prosecutors denied Abu Ali, who was enrolled at the Islamic University of Medina in Saudi Arabia at the time of his arrest, was ever mistreated. They presented videotaped testimony from Abu Ali's Mubahith interrogators — the first time that the Saudis ever allowed their agents to testify in a U.S. criminal case, according to prosecutors — who said Abu Ali confessed immediately after being confronted with evidence obtained from other al Qaeda members.
A dermatologist testified for the government that the marks on Abu Ali's back were mere surface scratches that could have been caused by the most superficial of injuries.
Even if the jury believed Abu Ali gave a truthful confession, the judge had instructed them to disregard it if they believed it had been obtained through torture.
Abu Ali, dressed in a gray suit, swallowed hard before the verdict was read but otherwise showed little emotion.
His mother declined to comment after the verdict.
Abu Ali's parents, who were born in Jordan and live in Falls Church, had fought to have him returned to the United States during the 20 months he was held in Saudi custody after his June 2003 arrest. The family even filed a lawsuit in federal court seeking his return. That lawsuit was rendered moot in February when Abu Ali was returned to the United States to face charges.
Defense lawyers sought to have the confession tossed out and the case dismissed at last month's pretrial hearing. But U.S. District Judge Gerald Bruce Lee allowed the prosecution to go forward, saying he had doubts about the credibility of Abu Ali's account.
The confession's admissibility is likely to be a significant issue in the appellate courts.
When prosecutors filed charges in February, many outside analysts questioned whether a conviction could be obtained. Prosecutors could not use a confession Abu Ali gave to the FBI in September 2003 because agents ignored his request for a lawyer, deciding at the time that the intelligence information he could provide was more valuable than preserving a possible criminal case.
U.S. Attorney Paul McNulty said in a statement that "the evidence presented in this case firmly established Abu Ali as a dangerous terrorist who posed a grave threat to our national security. ... It serves as a clear warning to all that terrorists can and will be brought to the bar of justice."