Frank R. James entered a Brooklyn subway station early Tuesday morning with an “entirely premeditated” plan to unleash a barrage of bullets into a car of commuters, an attack that federal prosecutors said in a Thursday court filing could have ended in a slaughter.
Mr. James, 62, is expected to appear in federal court in Brooklyn on Thursday, the first major step in a case that has shocked New Yorkers, a bloody shooting on a subway train that prosecutors said injured at least 30 people as smoke filled the car, gunfire broke out and chaos erupted.
The shooting represented the worst crime on New York’s public-transit system in nearly four decades. And it appeared that Mr. James was well prepared to evade capture, the filing said. He arrived at the subway station in the Sunset Park neighborhood in a disguise: a yellow hard hat and orange workman’s jacket with reflective tape, according to the court papers.
On the train, he fired “approximately 33 rounds in cold blood at terrified passengers who had nowhere to run and nowhere to hide,” federal prosecutors wrote. “Numerous passengers could have been killed.”
Mr. James is charged with carrying out a terrorist attack on a mass transit system, and faces up to life in prison if convicted. A court-appointed lawyer for Mr. James did not immediately respond to requests for comment.
Thursday’s filing asks a magistrate judge to detain Mr. James pending trial, citing his “severe and ongoing risk to the community.” Federal prosecutors said that while Mr. James’s lengthy arrest record — nearly a dozen low-level offenses, including reckless endangerment, larceny and trespassing — might seem “unremarkable,” it paints “a picture of a person with a penchant for defying authority and who is unable or unwilling to conform his conduct to law.”
The court papers offered clues about how the government planned to address the attack; the gunman’s motive remains an unanswered question, though Mr. James posted many videos on social media recording his furious complaints on a wide variety of topics.
It also remained unclear why a train line that cuts through immigrant-heavy neighborhoods in Brooklyn, like Sunset Park, a home to immigrants from many Asian and Latin American countries, became the target of a brutal shooting. And it was uncertain what Mr. James did between the time of the attack and his capture the next day.
In the hours after the shooting, the police discovered a collection of belongings on the train, including a Glock 9-millimeter handgun, three ammunition magazines and a credit card with Mr. James’s name on it. They also found ammunition and other weapons in a storage unit and apartment rented by Mr. James, prosecutors noted.
He was captured by the authorities on Wednesday afternoon, near a McDonald’s in the East Village, about 29 hours into an expansive manhunt that featured several federal and state agencies and hundreds of officers.
The arrest took place without a struggle as a rush of calls, videos and tweets poured in from New Yorkers saying they had helped identify him or had spotted him before his arrest. Mr. James, too, may have called a police tip line to report himself, according to at least two law enforcement officials with knowledge of the investigation.
The shooting arrived at a tense moment for New Yorkers, as the city attempts to contain a spate of violent crimes and rebuild civic life reordered by the pandemic. Other high-profile attacks in the subways present a daunting obstacle to restoring former ridership levels on a system that is key to the city’s economy.