Federal prosecutors brought terrorism charges Wednesday against the man accused of driving a truck down a bike path near the World Trade Center on Tuesday, striking and killing eight people.

29-year-old Sayfullo Saipov appeared in the New York federal courthouse handcuffed and with his feet shackled.

Prosecutors Saipov 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.

Acting U.S. Attorney Joon Kim said Wednesday federal prosecutors have charged Saipov with two terrorism-related crimes in the Tuesday rampage.

Prosecutors say he was stopped a "brave'' police officer, who shot and wounded him Tuesday. They say Saipov had been planning the attack for months.

Even as he lay wounded in the hospital from police gunfire, 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 faced charges that could bring the death penalty. He 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.

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, shot, or run over by a tank.

Saipov left behind knives and a note, in Arabic and English, which 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.

The FBI said around 5 p.m. that they were looking for information on a second person in connection to the attack.

About an hour later, New York FBI tweeted that they found 32-year-old Mukhammadzoir Kadirov, also known as Muhammad Kadirov, who is from Uzbekistan, and are still looking for any information the public may have on him.

The FBI did not release any further information, and it is not confirmed if Kadirov knows Saipov. Kadirov has not been identified as a suspect.

Officials are asking the public to contact the FBI in-person at a local FBI office, at 1-800-225-5324, or to contact the nearest American embassy or consulate.

Tuesday's terror attack killed five people from Argentina, one from Belgium, and two Americans, authorities said. 12 people were injured; nine remained hospitalized in serious or critical condition. Their injuries range from trauma to full amputations.

At a press conference at 1 Police Plaza on Wednesday, Mayor Bill de Blasio joined Gov. Andrew Cuomo and NYPD brass, urging New Yorkers to be patient and strong as details of the investigation come to light.

The NYPD identified the eight of the victims killed in the attack Wednesday afternoon.

Five Argentinian citizens killed in the attack had already been identified by the Argentine foreign ministry. They said Hernán Diego Mendoza, Diego Enrique Angelini, Alejandro Damián Pagnucco, Ariel Erlij, and Hernán Ferruchi were in New York City celebrating the 30th anniversary of their graduation from high school.

Another victim was identified by police as 31-year-old Anne Laure Decadt, a Belgian citizen.

The two other victims were 23-year-old Nicholas Cleves of Manhattan and 32-year-old Darren Drake of New Jersey.

During the last few weeks, Saipov searched the internet for information on Halloween in New York City and for truck rentals, Tyree 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.

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

John Miller, the deputy New York police commissioner for intelligence, said Saipov "appears to have followed, almost exactly to a T, the instructions that ISIS has put out.''

In the past few years, the Islamic State has exhorted followers online to use vehicles, knives or other close-at-hand means of killing people in their home countries. England, France, and Germany have all seen deadly vehicle attacks since mid-2016.

A November 2016 issue of the group's online magazine detailed features that an attack truck or van should have, suggested renting such a vehicle, and recommended targeting crowded streets and outdoor gatherings, according to the SITE Intelligence Group, a militant-monitoring agency.

Carlos Batista, a neighbor of Saipov's in Paterson, New Jersey, said he had seen the suspect and two friends using the same model of rented truck several times in the past three weeks.

It was not clear whether Saipov had been on authorities' radar. Miller said Saipov had never been the subject of a criminal investigation but appears to have links to people who have been investigated.

President Donald Trump called Wednesday for eliminating the 1990s visa lottery program that Saipov used to come to the U.S. in 2010, and the Republican president said he would consider sending Saipov to the Guantanamo Bay detention center — an idea the White House reinforced by saying it considered Saipov to be an "enemy combatant,'' a designation meaning someone could face a military tribunal and not have the same rights as someone in a U.S. court.

Hours later, Saipov was charged in federal court with providing material support to a terrorist group and committing violence and destruction of motor vehicles, resulting in death. Trump's administration could, at least in theory, still send the suspect to the U.S. base in Cuba later, though such a step would be unprecedented.

"There's no legal impediment to that,'' said Bryan Broyles, the former deputy chief defense counsel for the Guantanamo military commissions.

Late Wednesday, Trump took to Twitter to say that Saipov should get the death penalty.

Saipov is a legal, permanent U.S. resident. He lived in Ohio and Florida before moving to New Jersey around June, authorities said.

Birth records show he and his wife had two daughters in Ohio, and a neighbor in New Jersey said they recently had a baby boy.

Saipov was a commercial truck driver in Ohio. He also has worked as an Uber and Lyft driver.

In Ohio, Saipov was an argumentative young man whose career was falling apart and who was "not happy with his life,'' said Mirrakhmat Muminov, a fellow truck driver from heavily-Muslim Uzbekistan.

"He had the habit of disagreeing with everybody,'' Muminov said.

"He said he and Saipov would sometimes argue about politics and world affairs, including Israel and Palestine. He said Saipov never spoke about ISIS, but he could tell his friend held radical views.

Investigators on Wednesday cordoned off an apartment building in a Patterson, New Jersey neighborhood where they believe Saipov lived.

Investigators say he drove a rented Home Depot truck into the bike path at West and Houston Streets around 3 p.m. Tuesday.

Officials say Saipov was from Tampa and rented the vehicle about an hour before the attack at a Home Depot in New Jersey.

Police rushed to the Passaic store and found a mini-van with Florida tags parked there.

Police say Saipov drove the rental truck into a crowd of pedestrians and bicyclists before colliding with a school bus near Stuyvesant High School.

He was shot in the abdomen by NYPD officer Ryan Nash, a five-year veteran, after jumping out of the truck with what turned out to be a paint ball gun and a BB gun and shouting "Allahu Akbar!,'' or "God is great'' in Arabic, officials said.

Schools Chancellor Carmen Farina said two staff members and two students were injured when the truck hit the school bus.

One of the students was in critical condition as of Tuesday night. Officials have not released the students' ages.

"This was an act of terror, and a particularly cowardly act of terror aimed at innocent civilians, aimed at people going about their lives who had no idea what was about to hit them,'' de Blasio said Tuesday after the attack.

New York and other cities around the globe have been on high alert against attacks by extremists in vehicles. The Islamic State has been exhorting its followers to mow down people, and England, France and Germany have all seen deadly vehicle attacks in recent months and years.

Cuomo called it a "lone wolf'' attack and said there was no evidence to suggest it was part of a wider plot.

Speaking with NY1 on Wednesday morning, Cuomo urged New Yorkers to not let the terror act deter them from carrying on with their everyday lives."

"We lost eight lives, and it was horrendous and it was terrible and we cried, but ultimately, they failed. They did not instill terror. They did not disrupt. There was not mayhem. New York is New York. We're stronger, better, and stronger than they are. These are depraved cowards, and we don’t react to depraved cowards," Cuomo said.

Police Commissioner James O'Neill said a statement the driver made as he got out of the truck and the method of attack led police to conclude it was a terrorist act.

A family friend with whom Saipov stayed in Ohio, Dilnoza Abdusamatova, told The Cincinnati Enquirer that Saipov was "really calm'' and worked hard.

"He always used to work,'' Abdusamatova said. "He wouldn't go to parties or anything. He only used to come home and rest and leave and go back to work.''

Officials said around 7 p.m. Wednesday that West Street is fully reopen to traffic, after it was closed due to law enforcement continuing its investigation of the area.

On Twitter on Tuesday, President Trump called it "another attack by a very sick and deranged person'' and declared, "NOT IN THE U.S.A.''

He followed up Wednesday morning with a tweet slamming New York's senior senator.

He tweeted, "The terrorist came into our country through what is called the 'Diversity Visa Lottery Program,' a Chuck Schumer beauty. I want merit based."

Schumer responded by tweeting, "I guess it's not too soon to politicize a tragedy."

De Blasio came to Schumer's defense, tweeting, "@SenSchumer secured the funds to protect NYC after 9/11. No one has done more to keep us safe. POTUS should unify us, not politicize tragedy."

While police did not specifically blame the Islamic State for the New York bloodshed, Trump railed against the extremist group, tweeting, "We must not allow ISIS to return, or enter, our country after defeating them in the Middle East and elsewhere. Enough!''

At least two covered-over bodies could be seen lying on the path of the attack, and the front end of the pickup was smashed in, as was the side of the school bus.

Tom Gay, a school photographer, heard people saying there was an accident and went down to West Street, where a woman came around the corner shouting, "He has a gun! He has a gun!''

Gay said he stuck his head around the corner and saw a slender man in a blue track suit running on West Street holding a gun. He said there was a heavyset man pursuing him.

He said he heard five or six shots, and the man in the tracksuit fell to the ground, gun still raised in the air. He said a man came over and kicked the gun out of his hand.

Farina said trauma counselors will be provided in the schools Wednesday.

A Home Depot Inc. spokesman said the company, based in Atlanta, was "fully cooperating'' with law enforcement in the truck attack investigation.

The ride-hailing service Uber confirmed late Tuesday night that Saipov was one if its drivers. The company said he passed a background check and had been actively driving on the platform for more than six months. He has since been banned from the Uber app.

"We are horrified by this senseless act of violence," the company said in a statement. "Our hearts are with the victims and their families. We have reached out to law enforcement to provide our assistance."

The FBI and NYPD are asking for any help with the investigation into the terror attack.

People are asked to share any images or videos at fbi.gov/nyctribeca

If you have any additional information, you are asked to call 800-225-5324, or the NYPD's Crime Stoppers Hotline at 1-800-577- 8477, or for Spanish at 1-888-577-4782.