A federal jury convicted Ahmad Khan Rahimi, a loner from New Jersey drawn to online calls to jihad and instruction manuals for carrying it out, of setting the explosives in the Chelsea neighborhood that blew out windows and sent shrapnel flying into buildings, cars and people during a two-day bombing campaign in and around New York City last year.
Mr. Ramini, 29, a stocky and bearded husband and father born in Afghanistan who lived most of his life in New Jersey, remained mostly expressionless in Federal District Court in Manhattan on Monday as he listened to a single word — “guilty” — called out over and over, eight times, by the jury foreman. He blinked rapidly and at times appeared to nod.
Terror attacks that kill and injure scores of people have become all too common around the world. The Chelsea explosion, which took no lives, was widely seen as a near miss. But its proximity to the site of the Sept. 11 attacks in Manhattan, and its callbacks to that day, sent shudders through the city 15 years later. The police have said there have been some two dozen terror plots against the city since then, the vast majority thwarted, but none that shook and smashed a block as strongly.
“Today’s verdict is a victory for New York City, a victory for America and its fight against terror, and a victory for all who believe in the cause of justice,” said Joon H. Kim, the acting United States attorney for the Southern District of New York, in remarks outside the courthouse.
William F. Sweeney Jr., the head of the F.B.I.’s New York office, praised the public “for how engaged they were as this was going on,” and asked that New Yorkers stay vigilant. John Miller, the New York Police Department’s deputy commissioner of intelligence and counterterrorism, called the joint investigation with federal authorities “seamless.”
Mr. Rahimi was charged with eight counts of transporting and setting explosives in New York for use as weapons of mass destruction. He was found guilty of all eight.
The conviction carries a mandatory life sentence; Judge Richard M. Berman set a sentencing date for Jan. 18. Mr. Rahimi’s lawyer, Sabrina Shroff, who said her office planned to appeal, delivered an unconventional closing argument to jurors on Friday, insisting on her client’s innocence in only one of the two bombs placed in Chelsea that night.
Jurors rejected that argument. After the verdict, one juror said that the evidence was “very overwhelming” and left no doubt of Mr. Rahimi’s guilt. Jurors were in agreement on most of the counts early in their four hours of deliberations, said the juror, who asked that his name be withheld because of the nature of the case.
Dozens of F.B.I. agents, police bomb-squad detectives, computer analysts and technicians presented evidence over eight days of trial testimony. They had sorted through a blocklong field of debris on West 23rd Street and feeds from dozens of video cameras in the days after the Sept. 17, 2016, explosion, searching for clues and glimpses of a suspect who made no effort to hide himself that night.
Jurors also heard from those wounded by shrapnel from a bomb specifically designed to maim people. That no one was killed was a remarkable stroke of good fortune when the magnitude of the explosion became clearer. It blew out windows and doors and left debris on the rooftops of buildings. It threw a heavy trash bin across a street six lanes wide; the mangled metal container was rolled out for inspection by jurors hearing the trial.
Mr. Rahimi carried multiple bombs — nine in all — but most did not explode. The first was set early that morning in a garbage can at the finish line of a United States Marine Corps charity race in Seaside Park, N.J. The race’s start time was delayed, however, by an unexpectedly high turnout, and no one was hurt when the bomb exploded. That night, the blast occurred in Chelsea. A short time later, passers-by found a bomb on West 27th Street, which was disarmed by the police bomb squad.
The next day, Mr. Rahimi returned to New Jersey, leaving six pipe bombs in a backpack at an Elizabeth, N.J., train station. They carried fuses, not timers, and while they were not set to explode, they were dangerous; bomb-squad officers unintentionally detonated one later with a robot.
Mr. Rahimi was identified by his fingerprints and DNA on the unexploded devices and debris from the bombs. Video from cameras along the length of his journey from Pennsylvania Station in Manhattan, where he arrived from New Jersey that Saturday evening with his bombs, to West 23rd and West 27th Streets, were played for jurors over several days. Unhurried, his face without expression, Mr. Rahimi walked along the city’s sidewalks, pulling a rolling suitcase with each hand. He left one on West 23rd, the other on West 27th.
The first exploded at about 8:30 p.m. Camera after camera on the block showed smiling pedestrians, until a white blast of light filled the air. On the videos, the same pedestrians fled, their hands over their ears.
Later that night, on 27th Street, two men saw a suitcase on the sidewalk. One bent to open it, removing an object wrapped in a plastic bag — it was a pressure cooker packed with shrapnel and attached to a cellphone detonator. They took the empty suitcase. A neighbor passed, noticed the device and, rattled by the nearby explosion, called the police.
Ms. Shroff, the defense lawyer, told jurors that Mr. Rahimi had a change of heart after hearing the explosion from his first bomb, and disarmed the second device. The jury’s foreman, who, like the other juror, spoke on the condition of anonymity because of the nature of the case, said the group did not buy that theory.
“We were ultimately convinced the 27th Street device was in fact set, and while it did not go off, that was not a compelling reason to give us doubt as to the intent of the device,” he said.
The foreman, from Manhattan, said the trial was a personal reminder of everyday risks. “It’s hard to be a New Yorker who is not always looking around,” he said.