The delay this time was of the prosecutors' own doing. On Thursday they appealed a ruling by the judge, Shira A. Scheindlin of the Federal District Court in Manhattan, who had decided that the government could not call grand jurors to testify at the trial about their personal impressions of the defendant's demeanor when he appeared before them in October 2001. Such testimony, Judge Scheindlin found, would be overly speculative.
The accused, Osama Awadallah, is charged with committing perjury before the grand jurors concerning how well he knew one of the hijackers, Khalid Almihdhar, whose name, Mr. Awadallah told them, he could not even remember. One defense lawyer, Jesse Berman, has said that Mr. Awadallah misspoke to the grand jury because he was disoriented, exhausted and frightened after three weeks in solitary detention.
Mr. Awadallah, now 25 and a full-time student at San Diego State University, has never been charged with conspiring in or knowing about the Sept. 11 attacks. But he was arrested as a material witness on Sept. 21, 2001, having come under suspicion when F.B.I. agents found a scrap of paper with the name "Osama" and an old telephone number of his in a car left behind at Dulles International Airport by Nawaf Alhazmi, another of the hijackers who steered a plane into the Pentagon.
Court documents show that Mr. Awadallah was held for 21 days in solitary confinement. In court yesterday, his lawyers cited evidence that he had seven visible bruises when he appeared before the grand jury, marks they said had come from rough handling by prison guards during his detention.
The defense also argued yesterday, unsuccessfully, for dismissal of the case because Mr. Awadallah was handcuffed to a chair when he went before the grand jury. One of his lawyers, Elizabeth Fink, argued that the handcuffs had made him "look absolutely like a criminal" during questioning by a prosecutor, Robin Baker.
"Oy vey, what is he going to do, go out the windows?" Ms. Fink said to the judge, basing her argument on a Supreme Court decision in May holding that it was unconstitutional to use shackles in court on a prisoner convicted of a capital crime.
Mr. Awadallah's crime, she said, "is being a Jordanian citizen of Palestinian descent who is of the Muslim faith."
Witnesses before grand juries are not entitled to have lawyers with them inside the grand jury room, and Ms. Fink said that since Mr. Awadallah, handcuffed to the chair, had been unable to leave the room to speak with his lawyers, he had been deprived of his right to legal counsel.
Judge Scheindlin rebuked the prosecutors for use of the handcuffs, calling it "poor judgment." She also scorned Ms. Baker's statements to the grand jury that Mr. Awadallah had been held only "briefly" before his appearance there.
But the judge rejected Ms. Fink's arguments that Mr. Awadallah had been deprived of his legal rights, noting that he had been allowed to leave the room during several breaks.
Judge Scheindlin threw out the case once, in 2002, ruling that a law allowing detention of material witnesses to ensure their presence in criminal proceedings did not apply to appearances before grand juries. But an appeals court overturned her decision.
Just as it appeared that the trial was imminent, prosecutors informed the defense in May that they planned to call several of the grand jurors to tell how Mr. Awadallah looked as he was testifying.
But Judge Scheindlin ruled last week, and reconfirmed in writing yesterday, that although the grand jurors could testify about what objective events occurred during the testimony, they could not discuss their personal impressions of Mr. Awadallah's presentation.
With that ruling now under appeal by the government, Judge Scheindlin told the trial jurors yesterday that while she was not dismissing them, she would allow them to resume their lives because she could not predict how long resolution of the appeal would take.
She also moderately lightened the terms of Mr. Awadallah's bail, saying he appeared to pose no risk of flight. And, after learning that the government had bought only a one-way ticket from California for him, she ordered marshals to pay for his return to await trial.