Abdullah el-Faisal is the first person to face trial under state laws passed after Sept. 11. But he was not in the city when the offenses he is accused of took place.
The New York Police Department’s target was 1,500 miles away and across the sea.
Abdullah el-Faisal, the man investigators wanted, had an international history as a promoter of extremism. He had been imprisoned in Britain for inciting hatred and soliciting murder before being sent home to Jamaica, where he established himself with a website and lectures. He had caught the attention of the department’s Intelligence Bureau after promoting jihad and encouraging the murder of Jews, Hindus and Americans.
None of the crimes New York prosecutors say he committed — which include spreading Islamic State propaganda and helping a woman who said she wanted to marry an ISIS fighter — occurred while Mr. Faisal was anywhere near the city. But in a Manhattan courtroom, Mr. Faisal, 59, has become the first person to go to trial under state laws adopted days after the Sept. 11 attacks in 2001 that made it a felony to give terrorists financial or other material support before an attack.
To make their case, New York investigators took on fake identities, chatted with Mr. Faisal via WhatsApp messages and Skype and even traveled to the Middle East. They established jurisdiction merely by communicating with Mr. Faisal from Manhattan.
Cyrus R. Vance Jr., who was the Manhattan district attorney when Mr. Faisal was indicted, said the far-flung investigation kept the city safe.
“Our defensive perimeter isn’t just the East River and the Hudson River,” Mr. Vance said. “This is someone who was inciting jihad who had the possibility of affecting the streets of Manhattan.”
But Mr. Faisal’s lawyers portrayed him as a big talker whose actions did not match his violent rhetoric and was swept up in a plan advanced by determined investigators. Detectives posed as militants and flattered Mr. Faisal, calling him “very smart” and referring to the United States as the “land of war” to win his trust.
“What the evidence will not show is that Mr. Faisal committed an actual act of terrorism,” said Alex Grosshtern, one of his lawyers, during opening statements.
Police Department officials did not respond to a request to discuss Mr. Faisal’s case, but the trial, which began in late November in State Supreme Court, reflects the priorities and ambitions of the agency and the district attorney’s office: They have seen Manhattan as a magnet for terrorists and, in initiatives all but unrivaled outside the federal government, assembled special teams to investigate and prosecute extremists.
Critics have said over the years that police intelligence officers — who typically operate in secret, do not wear badges or uniforms, and communicate with other officers only through handlers — have crossed boundaries.
In 2003, constitutional scholars and civil libertarians complained about a practice of collecting data about the politics of people arrested at antiwar protests. Undercover officers conducted covert surveillance of people in the United States, Canada and Europe who had planned to demonstrate at the 2004 Republican National Convention in Manhattan. And in 2011, the department came under widespread criticism for spying on Muslims in New York and New Jersey, prompting a federal judge to tighten rules governing intelligence operations.
“There is a question about the appropriate role of local law enforcement in creating what is essentially a shadow C.I.A.,” said Alex S. Vitale, a sociology professor at Brooklyn College who studies policing. He added that the question was particularly acute when the police are engaged in “international hunts that use up resources that the city could be using to address its own problems.”
Federal prosecutors have often been reluctant to take on terrorism cases based upon evidence gathered by the local police without the involvement of federal agencies or Joint Terrorism Task Forces, which were established to coordinate efforts, said Ali Soufan, a former F.B.I. agent who supervised international terrorism cases.
He said federal prosecutors may not have believed the Faisal investigation met their rigorous thresholds. (When Mr. Faisal was arrested, former and current law enforcement officials suggested that his helpful ties to a foreign government had made federal prosecutors hesitant to build a case against him.)
The current district attorney, Alvin L. Bragg, said in a statement that his office is well prepared, maintaining a counterterrorism program “staffed with talented attorneys and analysts who have deep expertise prosecuting complex cases that span borders.”
“New Yorkers know the horrors of terrorism, and Manhattan remains a unique target for both global and domestic terror plots,” he said.
Eugene O’Donnell, a former police officer and prosecutor who teaches at the John Jay College of Criminal Justice, said the New York Police Department, the nation’s largest, is positioned to handle such investigations effectively, in part because it has a large, ethnically diverse and “street savvy” pool of employees.
Testimony and records of email and text exchanges introduced into evidence provide an unusual glimpse into an Intelligence Bureau investigation that lasted nearly a year, during which city detectives inhabited fictional personas, adopted the language of terror and traveled to the Mideast.
In early 2016, a detective, Ilter Aykac, sent an email to Mr. Faisal, claiming to be a 24-year-old Turkish-American woman named Rojin Ahmed.
“I told him that I was a struggling female,” Mr. Aykac, now retired from the Police Department, testified last month. “I told him I needed help and advice.”
Posing as Rojin, Mr. Aykac sent flattering messages to Mr. Faisal, calling him “very busy and important,” according to evidence, and saying that there were “lots of kuffars in new York,” using a derogatory name for nonbelievers.
Mr. Faisal suggested that Rojin should consider marrying his stepson, Hannibal Kokayi, who lived in Washington, D.C., writing in a text message introduced as evidence that “hijra is on his mind” — using a term that prosecutors said meant traveling to join ISIS.
But Mr. Faisal’s wife, Nzingha Kokayi, told Rojin, “u lost trust” for asking her son “about plans outside of US,” adding: “Ppl get arrested everyday for discussing this topic.” Ms. Kokayi also asked: “Why do u refuse to skype or send a picture?”
The next day, a female detective who testified as Undercover 487, took over the role of Rojin from Mr. Aykac. She appeased Ms. Kokayi on a video call that was shown to the jury. Then, prosecutors said, she met with Mr. Kokayi in New York and Washington.
In late 2016, Undercover 487 told Mr. Faisal that she was in Jordan, according to records of a Skype call entered into evidence. Less than an hour later, evidence shows, Mr. Faisal texted her the phone number of an ISIS fighter in Raqqa, Syria.
The evidence also shows that Mr. Faisal agreed that someone whom Undercover 487 described as a “Pakistani sister” named Mavish could contact him.
So the New York Police Department deployed a third detective, a woman in her 20s who was born in Pakistan and testified as Undercover 716. She posed as a former medical student from New York who was working as a “patient transporter” in a hospital and could help treat injured ISIS fighters. In late 2016, evidence shows, she told Mr. Faisal by text message that she planned to “leave work for good,” adding that it was “for hijrah.”
“We will plan together,” Mr. Faisal wrote back, the records show, and the two communicated for weeks, with Mavish saying she wanted a husband who shared the “same beliefs.” Mr. Faisal first tried to convince Mavish to marry him, then asked if she would be willing to marry a Somali man in Canada or a Pakistani man in Britain.
Mr. Faisal had been apprehensive about communicating with someone in the United States, believing those exchanges could be monitored, Undercover 716 testified. So in early 2017, the New York detective flew to Abu Dhabi.
She sent him a selfie in front of the Sheikh Zayed Grand Mosque there, telling him she needed to find a way into ISIS territory. The department’s investigation then extended further: Mr. Faisal sent her a phone number for a fighter in Syria named Luqmaan Patel, records show.
Mr. Patel quizzed her on her background, Undercover 716 said, asking whether she had ever been married and how much she weighed. He asked, in text messages introduced as evidence, “Are you sure you want to come right NOW?!” and “Are you having doubts?” He then added in a voice mail message that he was in an area with heavy fighting. Undercover 716 replied, “I am not having any doubts.”
Text messages show Mr. Patel wrote that he would help Mavish and asked whether she wanted to marry him. She said yes and he later wrote, “I eagerly await you lol.”