A federal judge said yesterday that Ahmed Omar Abu Ali's contention that his Saudi jailers whipped his back so hard that it was bloody and throbbing seemed implausible because "all of the evidence" indicates the American student was not in pain a few days later.

In a 113-page opinion, U.S. District Judge Gerald Bruce Lee explained why he declined Monday to throw out statements Abu Ali made that implicated him in a plot to kill President Bush. The Falls Church man is charged with multiple terrorism counts, and his attorneys had said his statements were coerced.

Lee released his opinion on the same day that jury selection began at the Alexandria federal courthouse in Abu Ali's trial, which is expected to start next week and last about three weeks. His decision was a major victory for prosecutors because Abu Ali's statements form the crux of their case.

In his opinion, the judge took issue with Abu Ali's claim that he was tortured June 9 or 10 in 2003. Saudi witnesses who spoke to Abu Ali a day later and FBI agents who observed a Saudi interrogation of him June 15 that year testified that he moved freely and did not favor his back. He even rocked and swiveled in his chair, the Saudis testified.

"Mr. Abu Ali testified that after his brutal whipping, he was in such pain that he had to sleep on his stomach for two weeks,'' Lee wrote in the opinion. "Well, two weeks after the whipping of June 9 or June 10, 2003 would certainly include June 15, 2003, and all of the evidence points to the fact that Mr. Abu Ali was not experiencing the pain he now claims.''

The judge also questioned why Abu Ali, 24, could not recall what he was struck with, a point that prosecutors repeatedly made during a six-day hearing on the torture allegations that concluded last week. Abu Ali testified that his Saudi captors chained him to the floor of an interrogation room, shackled his feet and then whipped him.

"While Mr. Abu Ali dramatically recounted a brutal beating and humiliating treatment, it is noteworthy that Mr. Abu Ali could not recall, even by texture, shape or dimension, what hit him,'' Lee wrote. "Was it a cylinder? Belt? Whip? Stick? Baseball bat?''

Prosecutors declined to comment on Lee's opinion, which clarified a one-page ruling he issued Monday that allowed Abu Ali's statements to be admitted into evidence. Defense attorneys did not return telephone calls.

The torture allegations have hung over the high-profile case ever since Abu Ali's parents sued the U.S. government last year, contending it had condoned the torture of their son in Saudi Arabia. Lee's ruling is probably not the last legal word on the matter: Defense lawyers are expected to raise the torture allegations again at trial.

Abu Ali is charged with conspiracy to assassinate Bush and other terrorism counts in connection with an alleged al Qaeda plot, which prosecutors say envisioned a Sept. 11, 2001-style attack in the United States.

He was arrested in Saudi Arabia in June 2003 and held there before being flown back in February to the United States.

Prosecutors recently played in court a 13-minute videotape in which Abu Ali said he joined the al Qaeda plot out of anger at U.S. support for Israel. Lee said Abu Ali "exhibited unusual behavior" on that tape, including when he simulated cocking a weapon.

Even as he disputed Abu Ali's specific claims, Lee devoted three pages of his ruling to explaining why "torture will not be tolerated in the American justice system.''

"The Court would like to make a very clear statement that torture of any kind is legally and morally unacceptable,'' Lee wrote.