The suspect was identified by two law enforcement sources familiar with the investigation as Sayfullo Habibullaevic Saipov. He's from Uzbekistan in Central Asia but had been living in the US since 2010, sources said.
A senior law enforcement officer told CNN a note, written in English, was found in the truck that said the attack, which unfolded around 3 p.m. on Halloween, was done in the name of ISIS.
"This was an act of terror, and a particularly cowardly act of terror," New York Mayor Bill de Blasio said, "aimed at innocent civilians, aimed at people going about their lives who had no idea what was about to hit them."
An image taken from Twitter shows what appears to be the suspect, according to a senior law enforcement official.
Rented truck used
The incident is being investigated as terrorism, officials said. Witnesses reported the suspect was yelling "Allahu Akbar," according to four law enforcement sources. The FBI's Joint Terrorism Task Force is taking over the lead of the investigation.
After crashing the truck into a school bus, the suspect left the vehicle while displaying imitation firearms and was shot in the abdomen by a police officer, according to the NYPD.
A pellet gun and a paintball gun were recovered from the scene, officials said.
Just after the incident, news footage showed several mangled bicycles on the popular bike path as medics tended to the wounded in the background.
A suspect drove a white truck down a heavily trafficked bike path in New York City on Tuesday.
Six people were declared dead at the scene and two were pronounced dead at the hospital. At least 11 others were transported to the hospital with serious but non-life-threatening injuries, according to New York Fire Commissioner Daniel Nigro.
Five of those killed were Argentinians, a group of friends celebrating the 30th anniversary of graduates of the Polytechnic School in their hometown, the country's Ministry of External Affairs said in a statement.
A spokesman for Home Depot confirmed one of the company's rental trucks was part of an incident in lower Manhattan and said the company is "cooperating with authorities" in the investigation.
Saipov was born in the central Asian nation of Uzbekistan and came to the US in 2010, two law enforcement sources told CNN. He was married on March 25, 2013 to another Uzbek, Nozima Odilova, when he was 25 and she was 19 in Cuyhoga Falls, Ohio. Neither had been married before.
Law enforcement sources said Saipov most recently lived in New Jersey. Neighbors in Paterson, a New Jersey city of 140,000 northeast of New York City, said he lived there recently.
He also lived in Florida for a period, sources said.
For the past six months, he was an Uber driver. The company said he passed a background but has now been removed from the app.
Saipov had multiple interactions with law enforcement in several states, online records show.
He had traffic citations issued in Missouri and Pennsylvania. He was arrested by the Missouri State Highway Patrol in October 2016 after a warrant was issued when he failed to show in court for a misdemeanor offense. He paid a $200 bond, which he forfeited when he didn't show up in court for his next hearing in November. A guilty plea was entered on his behalf.
News footage showed crowds of spectators -- some capturing the scene with cellphone cameras -- gathered behind police lines. A white Home Depot truck with the front end smashed was also visible.
Eugene Duffy said he had just left work at Pier 26 and was waiting on the light to cross West Street when he heard a scream. He thought it might have been a Halloween prank but he said the scream was bloodcurdling.
"I look down and I see a white pickup truck a couple of more blocks down in the bike path," he said. "Automatically, I know something's wrong. Then, as I go down more toward where the girl is screaming, I see two gentlemen laying there and they have tire tracks marked across their bodies. You could tell they both weren't here."
He continued to walk closer to the scene. Gunshots rang out. He saw police officers ducking for cover. A yellow school bus was smashed nearby. Police descended on the area.
"I thought automatically, this area, I thought it was terrorism," he said.
Parts of mangled bikes are strewn on the ground in Manhattan on Tuesday.
Michael Corbin, the assistant real estate manager for District Council 37, the city's largest public employees union, was standing outside the union's lower Manhattan offices attending to a woman who slipped and fell on the sidewalk.
"The first responder to the event was a counterterrorism officer," he said. "We were attending to the victim, getting her onto a stretcher and, at that moment, we heard gunshots. I recalled hearing five gunshots in quick succession and immediately the officer ... left to investigate the situation from the direction we heard the noise coming from."
Another witness, Ramon Cruz, described what he saw.
"What I saw was that the driver -- he didn't look like he was bleeding," said Cruz. "He was dragging his foot. He looks frustrated, panicked, confused. People are running past me, saying, 'He's got a gun. He's got a gun.' I didn't see any gun.
"It was a white pickup truck. He looked pretty bad without bleeding or anything like that. I didn't see him hit anybody. All I heard was the impact of a crash."
Tuesday afternoon on Twitter, a user posted an image of a person lying on the ground near the scene of an incident near West & Chambers Streets in Manhattan.
Authorities are sure to look at whether the suspect visited Uzbekistan since he moved to the United States seven years ago, CNN terrorism analyst Paul Cruickshank said.
"There has been a significant problem with jihadism in Uzbekistan," he said.
According to Cruickshank there are two large jihadi groups in the country. One of them is the Islamic Movement of Uzbekistan, which is affiliated with ISIS.
CNN's Jessica Schneider, David Shortell, Sonia Moghe, Ray