He Wouldn’t Become an Informant. Now He’s Headed for Prison.

NEW YORK — He was walking home from his consulting job at Iran’s U.N. mission in New York, his adopted city of many years, when the FBI agents approached. He was arrested, handcuffed and driven to a hotel.

The life of the consultant, Ahmad Sheikhzadeh, a naturalized U.S. citizen of Iranian descent with a doctorate from Columbia University and a network of prominent Iran contacts including its foreign minister, was altered on that day in March 2016.

In the hotel room where he was kept overnight, Sheikhzadeh recalled, the agents told him he could be imprisoned for decades on tax and sanctions violations if he did not become an informant. He had worked at the Iranian mission since 1990, preparing analyses of published articles on Iran and discussing them at weekly meetings.

Sheikhzadeh, a 62-year-old bachelor, migrated to the United States before Iran’s 1979 revolution and became a citizen in 2000. He surrounds himself with books in his New York City apartment, takes yoga classes and checks on older neighbors.

Friends and colleagues laugh at the idea that he could be a spy. But that is the image federal prosecutors sought to portray, describing his actions in court documents as having undermined “important economic controls that were put in place to protect the national security of the United States.”

His story offers a glimpse into how the estrangement between Tehran and Washington can upend the lives of Iranian-Americans, who are often mistrusted by one side or the other, or both, in relations that have become increasingly politicized.

Federal law enforcement officials had been monitoring Sheikhzadeh for years, eavesdropping on his emails and phone calls at least in part through warrants obtained from a Foreign Intelligence and Surveillance Act court.

They knew the Iranian mission had paid him cash for his consulting work, and that he had not reported at least some of the payments on his federal income taxes. They also knew that he had helped transfer thousands of dollars to friends and relatives in Iran without a Treasury Department license, violating U.S. sanctions.

Sheikhzadeh admitted those offenses to the agents, he and his lawyer, Steve Zissou, said in an interview, describing them as benign mistakes. But Sheikhzadeh refused to become an informant in exchange for lenient treatment.

“He made it unequivocally clear,” Zissou said. “His famous statement I’ll never forget was, ‘I’d rather spend the rest of my life in jail than cooperate with them, and spy against anyone else, spy against Americans, spy against Iran. It’s just not my way of doing things.'”

Sheikhzadeh agreed to plead guilty to two charges of tax and sanctions violations, and to pay more than $147,000 in fines and restitution. But prosecutors were not through with him, and suggested while he awaited sentencing that he was more of a threat than they could publicly disclose.

Their strategy ultimately failed, but not before Sheikhzadeh would undergo what he, his lawyer and his friends depicted as a Kafkaesque ordeal.

Insisting that he was a fugitive risk even though they had seized his U.S. and Iranian passports and his bank account, prosecutors persuaded Judge Pamela K. Chen of U.S. District Court to set bail at $3 million.

Further deferring to the prosecutors, the judge ordered Sheikhzadeh to wear a surveillance anklet, limited his travel to New York City and Long Island, and forbade him from going anywhere near the Iranian mission or contacting its staff.

“I’ve been here for over 40 years, then all of a sudden I commit the crime of the century and decide to go?” he said, recalling his reaction to the bail conditions.

Friends said the investigation took a toll on the normally upbeat Sheikhzadeh. “I can tell the investigation has been very hard on him,” Louise Jane Graham, a wardrobe stylist and yoga classmate, said in a letter to Chen urging leniency. The Iranian foreign minister, Mohammad Javad Zarif, who attended the same Tehran high school as Sheikhzadeh, complained about the case. Some Iranian officials called it a specious prosecution — an accusation U.S. officials often direct at Iran’s judiciary.

Sheikhzadeh’s network of relationships with influential Iranians may have piqued Washington’s interest long before his arrest. Besides Zarif, he was friends with Kamal Kharrazi, a former foreign minister and former U.N. ambassador.

A son of a wealthy Iranian businessman who bequeathed his children a generous inheritance, Sheikhzadeh was a teenager when he arrived in the United States.

While studying at the University of Houston, he watched in alarm as Ayatollah Ruhollah Khomeini overthrew the shah in 1979 and as Sheikhzadeh’s contemporaries seized the U.S. Embassy in Tehran and took American hostages.

In 1996, he earned his doctorate in political science from Columbia University. His dissertation committee included Gary Sick, a professor, Iran scholar and former national security adviser in the Ford, Carter and Reagan administrations.

“He’s a good guy, basically honest all the way through," Sick said. Sheikhzadeh’s job at the Iranian mission, Sick said, was “basically research work — a lot of people benefit from that, he’s made no secret about it.”

In his own letter of support for Sheikhzadeh to Chen, Sick wrote: “I am pleased to count him as a fellow American citizen.”

This was not the picture prosecutors wanted the judge to see. In June, while Chen was still deliberating the sentence, they released previously classified information suggesting that Sheikhzadeh had recruited Behrad Nakhai, an Iranian nuclear scientist who lived in the United States, to help Iran with its nuclear program.

The accusation blindsided Sheikhzadeh and his lawyer, who called it a politically motivated strategy to malign his client so the judge would impose a severe sentence. The accusation was never added to the other charges against him.

“Whatever they brought up is nonsense,” Nakhai, a specialist in nuclear power plant safety, said. “I’ve never seen a single centrifuge.”

In December, Zissou submitted a sentencing memorandum to Chen arguing that prosecutors had wrongly portrayed Sheikhzadeh as an agent of Iran — after their coercive attempt to recruit him had failed. Calling the conviction “the single blemish on a life that is in all other respects remarkable and admirable,” he urged the judge to spare Sheikhzadeh from prison.

Prosecutors urged the judge to ignore Zissou’s arguments, saying that, if anything, Sheikhzadeh’s punishment should exceed the federal guidelines of 46 to 57 months in prison, arguing it would “send an appropriate message.”

But on the day of sentencing last month in Brooklyn, it was the prosecutors’ turn to be blindsided. Zissou unexpectedly put his client on the witness stand.

“I was not a spy or undercover agent,” Sheikhzadeh said in court. “I did not hide my activity or my work at the mission. All of my friends knew — most of my friends knew. My family knew.”

During cross-examination, the prosecutors tried to suggest that Sheikhzadeh was hiding something. But in a moment that appeared to undercut them, Chen showed impatience.

“I feel like I am missing whatever it is the government is trying to convey to me,” she said. “I cannot figure out for the life of me what it is you think he is doing or what it is you think Mr. Sheikhzadeh did.”

John Marzulli, a spokesman for the U.S. attorney’s office in Brooklyn, said prosecutors would not comment on the hearing. Zissou said their strategy had “really backfired.”

The judge sentenced Sheikhzadeh to three months at a minimum-security prison camp. She also ordered the surveillance anklet removed pending a prison date.

“She finally realized the guy didn’t need it in the first place,” Zissou said.

It was a bittersweet moment for a man who had embraced life as an American. The government’s invasion of his privacy, Sheikhzadeh said, had especially galled him. “What rights do you have as a citizen?” he said.

He said he was unsure what he would do after his sentence was completed. “Teach, volunteer work — it’s, like, beyond my imagination,” he said. “I just can’t wait to get over with this case.”