When Ahmed Abassi arrived in the United States for the first time in March 2013, the Tunisian student settled into a historic, neo-Gothic apartment building in Manhattan’s Financial District.

Unknown to him, the apartment was wired with audio recording devices, and Abassi’s American host was an undercover FBI agent. Abassi, then 26 and suspected of terrorism ties, had landed in an FBI sting, part of an elaborate operation that stretched from New York to Quebec City to a small town in Tunisia.

Abassi was caught on tape discussing “the principle that America should be wiped off the face of the earth,” with people he believed to be co-conspirators, one of whom was the FBI agent, according to court records. At one point, Abassi suggested “putting bacteria in the air or in a water supply.”

But last month, Abassi, who declined to be interviewed, pleaded guilty to relatively minor charges that did not include any terrorism enhancements that could have sent him to prison for years, and he is not contesting a deportation order.

The case was a rare setback for the FBI and federal prosecutors, which have successfully targeted suspected terrorists using sting operations, typically ending with the defendants about to embark on what they believe is a terrorist attack with fake weapons or bombs supplied by the bureau. Guilty verdicts and long prison sentences follow.

Ahmed Abassi celebrating his 26th birthday in Tunisia, 2 months before his travel to New York in 2013. ( Courtesy of Abassi Family)

According to a recent report by Human Rights Watch, nearly 50 percent of the more than 500 federal counterterrorism convictions since the Sept. 11, 2001, attacks have “resulted from informant-based cases; almost 30 percent of those cases were sting operations in which the informant played an active role in the underlying plot.”

Among the more prominent prosecutions, a Moroccan man was convicted for planning a suicide bombing at the Capitol. Amine Mohamed El Khalifi, an illegal immigrant who lived in Alexandria, was arrested wearing a suicide vest that he believed to be real and had been provided by undercover FBI agents. In Portland, a Somali-American was convicted of planning to remotely detonate an 1,800 pound bomb at a Christmas tree lighting ceremony. The device was, in fact, inert and had been supplied by the bureau. In one 2009 case, the FBI arrested a group of men in New York state — the “Newburgh Four” — and charged them with plotting to blow up a pair of synagogues in the Bronx with fake bombs provided by an informant.

Human rights groups allege that the government is making terrorists out of people who otherwise would not have the ability or the will to move forward with an attack. “The government pursues people with mental or intellectual disabilities or people who are desperately poor with an aggressive informant or undercover agent to get them to agree to commit terrorist acts,” said Andrea Prasow, deputy director of Human Rights Watch’s Washington office.

And the use of sting operations has also drawn some criticism from the bench. In the Newburgh case, the federal judge said the government “made them terrorists” and said the “buffoonery” of one of the defendants was “positively Shakespearean in scope.”

But no defendant, including in the Newburgh case, has successfully claimed in court that he was entrapped by overzealous investigators.

At a recent security forum in Aspen, Colo., former FBI director Robert Mueller defended the bureau’s tactics against charges of entrapment. Mueller said agents and prosecutors go to great lengths to make sure they do not cross that line.

“We know at the outset that anytime we do this that the defense is going to be entrapment and there has to be substantial predication to get over that hurdle,” he said. “It’s been the defense in probably dozens of terrorism cases that have been tried since Sept. 11. And I challenge you to find one of those cases in which the defendant has been acquitted asserting that defense. I don’t believe there is one out there.”

Abassi was arrested last year and charged with two counts of fraud and misuse of visas to facilitate an act of international terrorism. Federal prosectuors in the Southern District of New York withdrew the terrorism enhancements against Abassi before they could be adjudicated, and some activists said an entrapment defense might have tested the government’s winning record.

An FBI spokesman in New York declined to comment.

Abassi was more talker than terrorist and resisted attempts to move beyond words to direct action, according to his attorney, Sabrina P. Shroff, a federal public defender. She described the case against her client as a failed entrapment in which the government attempted to prey on Abassi’s “bad thoughts and bad speech.”

Fateful meeting

Abassi first came to the attention of the FBI in Canada, where he was studying for an engineering degree at Laval University in Quebec City, according to court records. His family said his sister followed him to Canada, where he also met and married a Tunisian woman.

Among Abassi’s new circle of friends was Chiheb Esseghaier, a doctoral student. The FBI and Canadian authorities began to suspect that Esseghaier and Abassi were part of a terrorist cell, according to court records.

Esseghaier introduced Abassi to a man from New York, Tamer El Noury, who said he was born in Egypt and had immigrated to the United States when he was a child. He looked like one of Abassi’s favorite performers, a Syrian singer named George Wassouf. The two got along famously. When in Quebec, Noury came to Abassi’s house to eat.

Neither Abassi nor his wife, Yousra, ever suspected that Noury was an FBI agent.

“We had no idea,” his wife said in an interview.

The New Yorker appeared wealthy and said he ran a successful real estate company in the city. As a wedding gift, he said he would pay for Abassi and Yousra to visit Manhattan, she said.

Abassi declined the invitation, and instead he and his wife flew to Tunisia in December 2012 to renew their wedding vows. “We danced, we invited all our relatives and friends and we enjoyed together,” his wife said.

The euphoria didn’t last. That month, the Canadians revoked Abassi’s visa without explanation. Officials decided to test Abassi’s willingness to conduct an act of terrorism.

Noury began what Abassi’s attorney described as an aggressive campaign to get her client to come to New York from Tunisia. Cut off from his wife, who was able to return to Canada to finish her education, Abassi seemed determined to secure a new visa so he could return to her side. He wanted to finish his master’s degree, and he had a job offer with a major mining company. But no Canadian visa was forthcoming.

Noury called Abassi’s wife in February 2013.

“We can get him in New York where he can stay with me in the apartment, or he will have his own apartment, and if, God willing, you can take some time off from work, we can bring you here to stay with him so that you can spend some time together,” said Noury, according to a transcript of the call.

Abassi agreed to fly to New York after U.S. law enforcement arranged a visa for the “sole purpose of advancing the investigation,” according to court records.

Move to New York

In March 2013, Abassi flew to John F. Kennedy International Airport, where he was briefly questioned by immigration authorities. Noury met him at the airport.

The two drove to the downtown apartment, where the call to prayer sounded electronically five times a day to highlight Noury’s piety. The undercover agent provided Abassi with a cellphone and laptop. The rent was free.

An unexpected visitor soon arrived: Esseghaier, who said he was attending a scientific conference in New York.

The three men met frequently. Authorities say Esseghaier told Abassi about his plans for a terrorist attack. But Abassi did not want any part of them, frustrating the conspirator, who urged Noury to throw him out of the apartment. Esseghaier called Abassi “useless” and not a “true brother.”

Abassi continued to make inflammatory statements, however. He argued that the Koran allowed “Muslims to attack Americans in the same ways Americans had attacked Muslims, including the killing of women and children,” according to court records.

On April 22, 2013, Abassi was questioned by the FBI. Prosecutors said he lied repeatedly about his relationship with Esseghaier and whether he knew the Tunisian planned to engage in terrorism. The FBI arrested Abassi. That same day, Canadian authorities took Esseghaier and another man into custody, charging them with conspiracy to attack an Amtrak train traveling from New York to Toronto.

U.S. prosecutors said Abassi acknowledged possibly radicalizing Esseghaier, and that the two had talked about committing terrorist acts, according to court records. They said Abassi did not want to participate in Esseghaier’s plans only because “the number of American casualties from such an operation would be too few.”

Shroff said her client did not radicalize Esseghaier.

“If you actually listen to the conversations between Chiheb [Esseghaier] and Ahmed, you’ll realize Ahmed is talking about words and verses from the Koran,” his attorney said. “He’s telling Chiheb what’s in the Koran. That is not radicalizing.”

Authorities also said the men had received guidance from members of al-Qaeda.

A U.S. law enforcement official, speaking on the condition of anonymity to discuss sensitive details of the case, said the FBI had to end the U.S. operation against Abassi prematurely because the Canadians were concerned about the threat Esseghaier posed and arrested him.

The official said more will come out about the men, including Abassi, when Esseghaier goes on trial in Canada. The official said the men were part of a cell and presented a serious threat, one the FBI helped eliminate.

“It was a good case,” the official said.

Abassi spent months in jail, part of that time in a segregated housing unit, before his attorney received transcripts of the FBI recordings. Shroff said it was apparent to her that Abassi had not provided the evidence the FBI needed to make its case, that he had not stepped over the line into active participation in a plot.

Prosecutors seemed to reach a similar conclusion. They told Shroff they would drop the terrorism enhancements if Abassi agreed to plead guilty to the charges that included putting false information on an application for a green card — the same one the undercover agent helped him complete — and making a false statement to immigration officials.

“Mr. Abassi would not be asked at the time of the plea, if he accepted this offer, to in any way admit that either of these crimes touched on a crime of international terrorism,” Assistant U.S. Attorney Michael Ferrara told the judge during a hearing in April.

Ferrara would not discuss the case, but another U.S. law enforcement official said there were considerations if the case went to trial, including revealing the true identity of the FBI undercover agent.

“There were strategic discussions,” the official said. “We had a good undercover who would then be exposed. Was it worth it to get a couple of extra years in prison? It’s not clear the judge would have given him more time.”

The official added that Abassi pleaded guilty to a felony and “will never again be in the U.S. That’s much better than letting him float around out there and never be charged at all.”

For Shroff, the reason prosecutors backed off is clear: “He was entrapped,” she said.

At sentencing, prosecutors called for a longer prison term than the six months suggested by the guidelines, arguing that Abassi was far more dangerous than “simply an immigration fraudster” and had “dangerous, extremist views.”

In a phone interview, his sister Amira Abassi said: “My brother is not a monster. That is the reality. He is not evil.”

On July 16, Judge Miriam Cedarbaum waved away government calls for a stern sentence. The 84-year-old judge told Abassi to stay clear of trouble.

“I hope that you will think very seriously about the events of the last year and will decide to always abide by the laws of the United States,” she said. “And if you do that, I wish you good luck.”

Abassi is being held in an immigration detention facility in New Jersey, where he awaits deportation to Tunisia.