After 21/2 weeks of testimony, closing arguments in the terrorism trial of Ahmed Omar Abu Ali boiled down to one question: What happened to Abu Ali after he left his Falls Church home in September 2002 to go to school in Saudi Arabia?

Prosecutors said Abu Ali joined an al Qaeda cell after he arrived, adding that he began planning terrorist strikes to be carried out in the United States, including the assassination of President Bush. They said Abu Ali admitted to his Saudi jailers that he wanted to shoot Bush on the street or blow him up with a car bomb.

"The evidence overwhelmingly establishes that the defendant was recruited and trained to be an al Qaeda terrorist," Assistant U.S. Attorney Stephen Campbell told the jury yesterday in U.S. District Court in Alexandria.

But defense attorneys said Abu Ali remained what he always was: an American student who went to Saudi Arabia only to pursue religious studies. They said a false confession was forced out of him by brutal whippings in a Saudi jail.

"He is not a raving al Qaeda terrorist. He's an American kid; he's a polite kid," defense attorney Khurrum Wahid said. "He's a kid who went overseas and knew a guy who knew a guy, and he ended up sitting here."

The clashing views of Abu Ali, 24, animated the final day of one of the highest-profile terrorism trials since the Sept. 11, 2001, attacks. Abu Ali is charged with conspiracy to assassinate Bush and other counts of terrorism in what prosecutors say was a plot to carry out a Sept. 11-style attack inside the United States.

Today the jury will begin deliberating Abu Ali's fate. If convicted on the assassination count alone, he faces up to life in prison. He was arrested in Saudi Arabia in June 2003 and held there until he was flown back to the United States in February. His family had mounted an intense campaign to win his release.

The trial was in many ways a reprise of an earlier hearing that examined Abu Ali's contention that he was tortured by his Saudi jailers. Many of the same witnesses testified at both proceedings, including defense medical experts who said they found evidence of torture. Government experts rebutted that testimony. The primary areas of dispute were whether marks on Abu Ali's back were caused by whipping and whether he suffered post-traumatic stress disorder from the alleged abuse.

One key difference was that Abu Ali did not testify at his trial. In his testimony during the hearing, he described how his Saudi captors chained him to the floor of an interrogation room, shackled his feet and whipped him so hard his back was bloody and throbbing with pain.

But U.S. District Judge Gerald Bruce Lee ruled that he found the story "implausible" because Abu Ali could not describe what he was hit with and because he did not seem to be in pain just a few days later. The judge denied defense requests to throw out Abu Ali's confession but said the defense could raise the torture argument again at trial.

Wahid said in an interview that Abu Ali did not want to take the stand again because he found it to be "a painful experience."

"He testified at the hearing, he spilled his guts and he told the truth," Wahid said. "And the judge did not necessarily believe him."

Prosecutors have vehemently denied that Abu Ali was tortured, and yesterday Campbell called the allegations "completely manufactured." During the trial, prosecutors presented testimony from Saudi security officers, who said that Abu Ali was treated well and that he willingly confessed.

The officers testified via videotape from depositions they gave in Saudi Arabia.

Campbell said Abu Ali discussed crashing planes into targets in the United States, killing members of Congress and blowing up U.S. military aircraft with other members of his al Qaeda cell. He said Abu Ali admitted to the Saudis that he had been thinking about acting against the United States even before he joined the cell.

Wahid portrayed his client as a typical university student and questioned the Saudis' contention that other members of the al Qaeda cell had identified Abu Ali. "Do you think an al Qaeda guy is going to give up another al Qaeda guy," he said, "or did they pick some patsy they knew from the University of Medina?"

He said Abu Ali confessed because "those interrogations were designed to break his will, to break his ability to resist.''