I have been teaching modern Middle Eastern history for more than 20 years. I’ve helped train many graduate students, some of whom have gone on to become professors at universities across the country. But one of my current New York University graduate students, Mohammed Yousry, faces a very different future. Convicted a year ago of participating in a conspiracy to abet terrorism, he may be sentenced to as many as 20 years in federal prison.

Knowing Mohammed as I do, and having followed his trial closely, I am convinced that he is a victim of the kind of excessive prosecutorial zeal we have seen all too much of since 9/11. But his case is especially disturbing because what may put Mohammed behind bars is the work he did in good faith as a translator and an academic researcher. This would turn a travesty of justice into a very dangerous precedent.

A gentle and unassuming man, Mohammed came to this country from Egypt 25 years ago. He and his wife (an evangelical Christian) had a daughter who would eventually graduate from a Baptist college. Mohammed became a U.S. citizen. When I first met him in 1995, he was a graduate student at NYU, paying his tuition and supporting his family by driving a taxi and by working as a translator of Arabic for journalists and lawyers. One of the lawyers who hired Mohammed was Lynne Stewart, among whose clients was Sheik Omar Abdel Rahman, the blind former spiritual guide of a radical Islamist organization in Egypt who is now serving a life sentence for plotting to blow up New York City landmarks.

When Mohammed began to discuss possible doctoral dissertation topics with me seven or eight years ago, I encouraged him to write a political biography of Abdel Rahman, partly because his employment as a translator for Stewart gave him unique access to the imprisoned cleric. Though a lifelong secularist and democrat who totally rejects Abdel Rahman’s extremist version of Islam, Mohammed started gathering material on the cleric for his dissertation, and even interviewed him about his ideas and political career during government-authorized prison visits with Stewart.

Mohammed’s diligence as a translator and an academic researcher would cost him dearly. In April 2002, he was arrested, along with Stewart and one of her paralegals. They were accused of conspiring to provide material support to terrorists. Two years earlier, Stewart had told a reporter that the imprisoned Abdel Rahman opposed a cease-fire that his supporters had negotiated with the Egyptian government. Though no act of violence ever resulted, the U.S. government claimed that Stewart had not only violated government regulations — which she had agreed to follow — restricting communications with Rahman but that she had also abetted terrorism.

Whatever Stewart may have done, however, it is hard to see how Mohammed can be held responsible for her actions. As a government-approved translator, he was never even asked to agree to the regulations Stewart was accused of violating, and he had no reason to question the lawfulness of his employer’s instructions.

During the trial, prosecutors made contradictory arguments. They insinuated that Mohammed had knowingly broken the law in order to further his scholarly research, and even that he was an acolyte of Abdel Rahman. But they also acknowledged that Mohammed had never advocated violence or Islamic fundamentalism. My guess is that the real reason they went after Mohammed was to get Stewart: She knew no Arabic, and Abdel Rahman knew very little English, so without including Mohammed in the alleged conspiracy, prosecutors wouldn’t have had much of a case.

Mohammed, shell-shocked by what has happened to him, faces sentencing in March, though appeals will surely follow. Many lawyers have rallied to Stewart’s defense because they believe that the government targeted her in order to deter other lawyers from zealously defending clients accused of terrorism, and because they feel that her case raises serious constitutional issues. Mohammed’s prosecution raises somewhat different, though equally disturbing, questions. Should a translator be sent to prison for following his employer’s instructions, especially when the prosecution failed to prove that he intended to break any law? Can a graduate student’s dissertation research reasonably be construed as contributing to a conspiracy to help terrorists?

If Mohammed’s conviction is allowed to stand, we may well see other translators prosecuted for doing their jobs, and other scholars facing jail terms for conducting research on controversial issues. That would undermine core values we profess to cherish, including academic freedom and other civil liberties. It would also weaken our ability to understand Muslim extremism and successfully confront it.

Zachary Lockman chairs the department of Middle Eastern and Islamic studies at New York University. This article originally appeared in the Los Angeles Times and is reprinted by permission of the author.