The man charged with opening fire in a Brooklyn subway car full of people was jailed without bail Thursday as prosecutors told a judge he terrified all of New York City.

Brought into a Brooklyn federal court without handcuffs, a subdued Frank James, 62, softly answered standard questions about whether he understood the charges and the purpose of the brief hearing. His lawyer later asked the public not to prejudge him.

James was arrested in Manhattan after calling a police tip line to say where he was Wednesday, a day after the nightmarish rush-hour attack left 10 people with gunshot wounds and countless others fearing for their safety on the nation’s busiest subway system.

Authorities say he unleashed smoke bombs and dozens of bullets in a train full of morning commuters. He’s charged with a federal terrorism offense that applies to attacks on mass transit systems — authorities say there’s currently no evidence linking him to terror organizations and are still trying to derive a motive.

“The defendant terrifyingly opened fire on passengers on a crowded subway train, interrupting their morning commute in a way the city hasn’t seen in more than 20 years,” Assistant U.S. Attorney Sara K. Winik said, apparently referring to the Sept. 11, 2001, attacks.

“The defendant’s attack was premeditated, was carefully planned and it caused terror among the victims and our entire city,” she said.

While James was in court, Hourari Benkada was in a hospital bed with a bullet wound in his leg.

Benkada said he was just feet away from the gunman on the train and has struggled to sleep since. Tuesday’s horrific scene keeps replaying in his mind.

“I’m still shocked about it,” Benkada said in a video interview Thursday, grimacing in pain as he recalled the attack.

He had headphones on, music blaring, as smoke began filling the subway car. He initially thought it was a small fire. But the smoke “kept escalating to black, black smoke like 9/11,” he said, “and the whole train was pitch-black.”

Then there were gunshots, screams and a scramble for safety. Benkada said he tried to shield a pregnant woman from getting hit during the mayhem, and as people pushed forward, a gunshot tore into his knee.

The shooting victims, who range in age from 16 to 60, are all expected to survive.

Prosecutors described James in court papers as a calculating shooter who wore a disguise — a construction worker-style hard hat and jacket that were shed right after the attack — and fired “in cold blood at terrified passengers who had nowhere to run and nowhere to hide.”

But defense attorney Mia Eisner-Grynberg cautioned against “a rush to judgment.”

“Initial reports in a case like this are often inaccurate,” she said outside court. She noted that James alerted police to his whereabouts, 30 hours into a manhunt that included cellphone alerts to the general public.

Once he knew he was wanted, “he called Crime Stoppers to help,” Eisner-Grynberg said.

The manhunt began focusing on downtown Manhattan after police got a tip from a sharp-eyed high school junior on a photography class excursion.

Jack Griffin, 17, said he was looking for subjects for pictures when his eye was drawn to a man sitting on a bench with a duffel bag, resting amid the bustle of a street near Chinatown.

“As soon as I saw him, my first instinct was: ‘That’s him,’” Griffin said. He snapped some photos of the man, who mumbled something and quickly moved on. Then Griffin sent his photos to police, who dispatched officers to the area.

Eventually, police got 911 reports of other possible sightings — and they got a call from James, saying he was at a McDonald’s in the East Village neighborhood. He was gone when police got there, but bystanders spotted him and flagged down officers as they searched the neighborhood. James was apprehended a few blocks from the McDonald’s.

Two cousins, Zack Dahhan and Mohammad Cheikh, said they glimpsed the man and hastily looked up James’ wanted poster on their phones.

“And we say, ‘Oh, my God, this is the guy!’” as a number of people began to follow him, Dahhan said. The cousins said they pointed officers toward him.

James’ lawyers agreed Thursday to his being jailed, but said they could seek bail later.

At the request of James’ lawyers, Magistrate Roanne Mann said she would ask for James to get “psychiatric attention,” as well as magnesium tablets for leg cramps, at the federal lockup in Brooklyn where he’s being held.

Authorities say a trove of evidence connects James to the attack. His bank card, his cellphone and a key to a van he had rented were found at the shooting scene. Officers also found the handgun they said was used in the shooting; tracing records show James purchased the gun from a licensed gun dealer in Ohio in 2011.

In court papers, prosecutors suggested James had the means to carry out more more attacks, noting that he had ammunition and other gun-related items in a Philadelphia storage unit.

The New York City native had been living in Milwaukee and Philadelphia recently.

Investigators were examining many hours of videos that James posted on social media, as recently as Monday, in which he delivered profanity-laced diatribes about racism, society’s treatment of Black people, homelessness and violence. He also discussed his history of psychiatric treatment and complained about how New York’s mayor is dealing with homeless people on subways and with gun violence.

He also talked about shooting people, prosecutors noted in court papers.