NEW YORK -- For three years federal agents trailed Mohammed Yousry, a chubby 50-year-old translator and U.S. citizen who worked for radical lawyer Lynne Stewart. Prosecutors wiretapped his phone, and FBI agents shadowed and interviewed him. They read his books and notepads and every file on his computer.

This was their conclusion:

"Yousry is not a practicing Muslim. He is not a fundamentalist," prosecutor Anthony Barkow acknowledged in his closing arguments to a jury in federal district court in Manhattan earlier this year. "Mohammed Yousry is not someone who supports or believes in the use of violence."

Still, the prosecutor persuaded the jury to convict Yousry of supporting terrorism. Yousry now awaits sentencing in March, when he could face 20 years in prison for translating a letter from imprisoned Muslim cleric Omar Abdel Rahman to Rahman's lawyer in Egypt.

In June 2000, Stewart released to a reporter a version of the letter, which discussed a cease-fire between Islamic militants and the Egyptian government. Prosecutors said that the lawyer and the translator, by these acts, conspired to use Rahman's words to incite others to carry out kidnappings and killings. No attack took place.

"Kill who? What are they talking about?" Yousry asked recently as he sat alongside his wife, Sarah, an evangelical Christian, in their modest Connecticut condominium. "The words I'm looking for, it's insane."

The prosecution and conviction of Stewart, 66, on charges of aiding terrorist activity, drew international attention, overshadowing Yousry's case. But legal experts, civil liberties lawyers and a juror say Yousry's conviction raises many troubling questions, not least how a court-appointed translator working on instruction from lawyers could be held responsible for navigating complicated and dangerous legal waters.

The trial transcripts reveal that prosecutors advanced no evidence to back up certain claims, including the assertion that Yousry was in touch with Middle Eastern terrorists.

"You would expect a translator to take his lead from the defense lawyer and you would not expect that translator to understand the intricacies of a very broad criminal statute," said Neal R. Sonnett, a former federal prosecutor who chaired an American Bar Association task force that opposed the Bush administration's position on enemy combatants. "There is a real issue whether it's even fair to charge, much less convict, someone like him."

Yousry had no legal training and translated nothing without instruction from defense lawyers. He passed rigorous federal security clearance checks. A PhD candidate at New York University, Yousry harbored no affinity for Rahman, writing that the cleric promoted "Muslim totalitarianism."

Justice Department prosecutors said secret recordings of meetings in Rahman's prison showed that Yousry crossed the line between legal and illegal behavior. Yousry read letters to Rahman from radical supporters, even though he understood that they were violent men.

"He stuck his head in the sand and deliberately avoided knowing what would have been obvious," prosecutor Robin Baker told the jury. "We don't need to prove why."

Yousry was tried alongside Stewart, who supports armed revolution, and Ahmed Sattar, a Rahman aide and sympathizer with fundamentalist causes, in Manhattan, five blocks from Ground Zero. All three were convicted. Prosecutors played a videotape of Osama bin Laden and mentioned al Qaeda attacks, even though the case had nothing to do with that group.

A month after the trial, a female juror wrote to U.S. District Judge John G. Koeltl, complaining that fellow jurors talked of terrorist attacks and their desire to teach the defendants a lesson. "They had an agenda," Juror 39 told The Washington Post in her first interview. "People are so fearful that if you disagree with the government on one thing it makes you a terrorist.

"I have to plead guilty to being a coward," Juror 39, who spoke on the condition of anonymity, said of her vote to convict. "It doesn't feel good, but I punked out."

Out of Egypt

Yousry has round cheeks and curly hair, wears baggy sweaters and jeans and has the aspect of an absent-minded professor. He's far removed from a privileged upbringing in Egypt, where his father was a military general, a physician and a supporter of President Gamal Abdel Nasser.

Yousry came to New York City in 1980. He met Sarah, and they married in a church. Their daughter graduated from a Baptist college.

In 1995, Yousry's translation agency offered him a job with the legal defense team for Rahman, a prominent Egyptian radical who was accused of conspiring to blow up the United Nations building and the Holland and Lincoln tunnels. Yousry struck up a cordial if fractious relationship with Rahman, who speaks little English. "He liked to torture me about drinking and not praying and all that good stuff," Yousry recalled.

In October 1995, Rahman was convicted and sentenced to life in prison. Stewart and former attorney general Ramsey Clark, a courtly Texan with decidedly left-wing politics, set about trying to persuade the United States to transfer Rahman to an Egyptian prison. They asked Yousry to return to the case in 1997.

Yousry declined -- he wanted to write his dissertation and teach. His adviser, historian Zachary Lockman, suggested a marriage of academics and work. "Knowing that he would have access to the FBI tapes and to Rahman, I suggested a biography of Rahman and his movement," Lockman said. "I guess I'm responsible in a very sad way for the trouble he's in."

In April 1997, Attorney General Janet Reno imposed unprecedented restrictions known as "special administrative measures" on Rahman, denying him access to mail, newspapers and any visitor except his wife and attorneys. Prosecutors argued that Rahman's words were so dangerous that they constituted a weapon. Theirs was not an idle worry: Egyptian militants had slaughtered 58 tourists in Luxor in 1997 in hopes of forcing Rahman's release.

Clark and Stewart signed the administrative measures. Prosecutors did not demand the same of Yousry. The defense attorneys repeatedly tested the regulations. Clark in 1997 told reporters of Rahman's support for a cease-fire with the Egyptian government without earning a rebuke from prosecutors.

Prosecutors argue that the translator should have balked when the lawyers skirted the legal edge. This notion bemuses Clark. "Mohammed would assume that the lawyers knew what they were doing," he said in an interview.

Prison Meeting

By 2000, Stewart had taken the lead in Rahman's defense. A grandmotherly Maoist, she was an accomplished trial lawyer who eschewed Clark's diplomatic speech.

But Stewart did not realize that a year earlier Justice Department lawyers -- under the Foreign Intelligence Surveillance Act -- obtained permission to secretly videotape visits to Rahman in his maximum-security prison in Rochester, Minn. They also obtained wiretaps on Yousry and Sattar.

At the core of the government's case were two prison meetings with Rahman in May 2000. On May 19, Yousry read a note to Rahman from his radical followers, asking whether to maintain a cease-fire with the Egyptian government. Rahman dictated a response the next day. Contrary to prosecution claims, government tapes show the cleric did not favor ending the cease-fire.

"The militants," Rahman wrote to his attorney in Egypt, "should not cancel it altogether."

Stewart chattered to distract the guards and joked with Yousry that they could get in trouble. Prosecutors argued this was proof of a "red-handed" conspiracy. Yousry denied involvement, saying Stewart reveled in thumbing her nose at prosecutors.

On June 14, 2000, Stewart -- without Yousry's knowledge -- read a statement about the cease-fire to a Reuters correspondent. Misinterpreting Rahman's intent, she said he had withdrawn his support for it.

If this was a conspiracy, it was a remarkably uncoordinated affair. Four months later, Sattar, the postal clerk, released a fatwa, or religious edict, in Rahman's name urging followers to "kill Jews everywhere." Yousry, government tapes show, learned of the fatwa days later while reading the newspaper to Rahman. He immediately said he had to inform the lawyers.

"Mr. Yousry," Rahman snapped in a rare use of English, "this is none of your business!"

Later government tapes reveal Yousry upbraiding Sattar when he learned the postal clerk spoke to suspected terrorists after militants bombed the USS Cole in Yemen in October 2000. Yousry became worried. "I asked Ramsey what I should do," he recalled. "He told me: 'Listen to the lawyer and you'll be safe.' "

Indictment

A plume of black smoke rose from Ground Zero as four FBI agents knocked on the door of Yousry's home in Queens two days after Sept. 11, 2001. Yousry said little. Two more days passed, and he thought better of his reticence. He called the agents back and talked about Sattar and the USS Cole and Rahman. He met four more times with FBI agents over six months.

In the spring of 2002, a federal prosecutor suggested Yousry testify if the government indicted Stewart and Clark. This was confirmed by a federal law enforcement source. "They wanted me to entrap Lynne and Ramsey," Yousry said. "I said no."

On April 9, 2002, FBI agents and helmeted police officers with high-powered rifles came to arrest Yousry while his friends and neighbors peered behind cruisers and kitchen curtains. Stewart had been arrested that morning.

The FBI ultimately recorded thousands of hours of Yousry's telephone conversations and electronic activity over three years, but prosecutors introduced none of those tapes into evidence. Yousry never spoke to Rahman without the lawyers' permission, even when left alone with him. Nor, transcripts show, did the prosecutors offer evidence to back up assertions that Yousry talked to militants in the Middle East.

Prosecutors argued that Yousry metaphorically closed his eyes to the bad characters around him. They noted that he padded his résumé and suggested that he addressed Rahman as "spiritual master" to show allegiance; in fact, it's a common Arabic honorific. Prosecutors speculated that Yousry betrayed the nation in hopes of gaining a Harvard teaching position.

The jury began deliberations in early 2005 and conversation was not friendly to the defendants. "A woman was in tears she was so scared of terrorism," Juror 39 said. "Another kept asking why it took Yousry so long to finish his dissertation, that it was suspicious."

On Feb. 10, 2005, the jury foreman pronounced the defendants guilty on all counts. Yousry went ashen; his daughter, Leslie, dissolved in tears.

Afterward

Judge Koeltl recently rejected Yousry's legal appeal based on the account of Juror 39. The judge noted that juries are given great leeway. David Stern, Yousry's lawyer, cannot quite accept that. "I'm in the habit of defending bad people, and they've mostly done what they're accused of," he said. "This guy is flat-out innocent, and it's disgraceful he's going to prison."

Michael Gasper, who studied with Yousry and teaches at Yale, often visits the translator. The friends drink wine and laugh, and when Gasper leaves, Yousry presses another favorite history book into his guest's hands. The translator will have no use for them in prison. "The way he has taken it makes me cry, he's so gracious," Gasper said. "I try not to talk about it, but he keeps giving me those . . . books."

Yousry talks of hope. "I awake every morning and think: I will be vindicated," he said. "It just hasn't happened yet." But he passes the days until sentencing in his book-lined study. He figures it is the size of a prison cell and he wants to get used to it.