Bahij Chancey, 26, holds a photo of his friend, Nicholas Cleves, during an interfaith peace vigil Wednesday at Foley Square in response to the Manhattan truck attack Tuesday in New York. Cleves was one of eight people killed in the attack.

NEW YORK — Federal prosecutors brought terrorism charges Wednesday against the Uzbek immigrant accused in the truck rampage that left eight people dead, saying he was spurred to attack by the Islamic State group’s online calls to action and picked Halloween because he figured streets would be extra crowded.

Even as he lay wounded in the hospital from police gunfire, Sayfullo Saipov asked to display the Islamic State group’s flag in his room and said “he felt good about what he had done,” prosecutors said in court papers.

Saipov, 29, was brought to court in a wheelchair to face charges that could bring the death penalty. Handcuffed and shackled, Saipov nodded his head repeatedly as he was read his rights in a brief court proceeding that he followed through a Russian interpreter. He was ordered held without bail.

Outside court, his appointed lawyer, David Patton, said he hoped everyone lets the judicial process play out.

“I promise you that how we treat Mr. Saipov in this judicial process will say a lot more about us than it will say about him,” Patton said.

Meanwhile, the FBI was questioning a second person from Uzbekistan, 32-year-old Mukhammadzoir Kadirov. A law enforcement official said Kadirov was a friend of Saipov’s and may not have any role in the case. The official wasn’t authorized to speak publicly and spoke on condition of anonymity.

Prosecutors said Saipov had 90 videos and 3,800 photos on one of his two cellphones, many of them ISIS-related pieces of propaganda, including images of prisoners being beheaded or shot.

Saipov left behind knives and a note, in Arabic and English, that included Islamic religious references and said, “Islamic Supplication. It will endure,” FBI agent Amber Tyree said in court papers. “It will endure” commonly refers to ISIS, Tyree said.

Questioned in his hospital bed, Saipov said he had been inspired by ISIS videos and began plotting an attack about a year ago, deciding to use a truck about two months ago, Tyree said.

During the last few weeks, Saipov searched the Internet for information on Halloween in New York City and for truck rentals, the agent said. Saipov even rented a truck on Oct. 22 to practice making turns, and he initially hoped to get from the bike path across lower Manhattan to hit more pedestrians on the Brooklyn Bridge, Tyree said.

Saipov considered displaying ISIS flags on the truck during the attack but decided it would draw too much attention, authorities said.