A family friend described the suspect as calm and hard-working, while President Donald Trump derided him as "sick and deranged." A picture of the man's life only just began to emerge in the immediate hours after the Tuesday attack that killed at eight people and injured 11 more.
A look at what is known about the suspect:
Officials who were not authorised to discuss the investigation and spoke on condition of anonymity said the suspect is 29 and originally from Uzbekistan.
He came to the US legally in 2010, the officials said, and it is believed that he lived first in Ohio after his arrival.
An acquaintance, Dilnoza Abdusamatova, said he briefly stayed with his family in a Cincinnati suburb upon immigrating.
"He always used to work," Abdusamatova told The Cincinnati Enquirer. "He wouldn't go to parties or anything. He only used to come home and rest and leave and go back to work."
Drawn to Florida
Authorities said he had a Florida driver's license and some public records showed an address for him at a Tampa apartment complex.
Residents at that complex said FBI agents came by Tuesday evening and conducted interviews.
Michael Roberts, 30, an overnight shift worker, said he was asleep when the agents showed up at about 5:30pm but that they interviewed his cousin. He said both he and his cousin had moved in only a week ago and had never heard of the suspect.
A friend who met the suspect in Florida, Kobiljon Matkarov, told The New York Times and the New York Post that he seemed like a "very good guy".
"My kids like him too. He is always playing with them," Matkarov told the Post.
Officials said the suspect was living recently in New Jersey, where he allegedly rented a Home Depot pickup truck an hour before driving it onto the bike path.
On Tuesday night, police investigating the deadly rampage surrounded a white Toyota minivan with Florida plates parked in the parking lot of a Home Depot in Passaic, New Jersey.
The van was parked near the company's rental trucks.
The ride-hailing company Uber said he passed its background check and drove for the service for six months, making more than 1,400 trips.
The company said it banned him from the service after the attack. It said it was in touch with the FBI and offered its assistance and that it was reviewing the suspect's driving history but found no related safety reports.
Records show he was a commercial truck driver who formed a pair of businesses in Ohio.
The first business, Sayf Motors Inc., used the address of a family friend near Cincinnati with whom he had stayed for a couple of weeks after his arrival in the country.
The second, Bright Auto LLC, used an address near Cleveland.
A trucking industry website listed him at a Paterson, New Jersey, address that authorities were searching Tuesday night. Court records related to trucking-related infractions list the suspect with addresses in Paterson and the Cleveland suburbs.
According to the records, a warrant was issued for his arrest in April 2016 when he missed a hearing on a misdemeanor for not having the right brakes on his vehicle. He resolved the case in November 2016 by pleading guilty and paying $200 in fines and court costs.
No social media accounts linked to the suspect emerged immediately after the attack, but there were possible clues to his personal life.
A marriage license filed in Summit County, Ohio, lists the suspect as a truck driver. His wife is about six years younger. Both list Tashkent, Uzbekistan, as their hometown.
(FRANCE 24 with AP)