New York (CNN) The last time Sayfullo Saipov talked to Makhina Kadirova he was working his way toward the American dream.

It had been one year since Saipov left Uzbekistan and came to the United States on a diversity visa. He reached out to Kadirova on social media in 2011. She was a former classmate of his from early elementary school through ninth grade, also living in America.

"He was happy that he was here, he had a family here, and he was a truck driver and his business was really good," Kadirova says.

Kadirova remembers meeting Saipov as a 5-year-old. He was quiet. Calm, even. As they grew up together and until they were about 16 years old in their ninth-grade class in private school, he was active and "didn't do any bad things."

Crazy? That's not the "very kind boy" she remembers.

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And certainly not the terrorist being portrayed on TV after allegedly ramming a rented Home Depot truck into a crowd of pedestrians and bicyclists in lower Manhattan, killing eight and injuring more than a dozen.

As investigators begin to piece together the life of a man accused of planning an attack in the name of ISIS, those who crossed his path are trying to reconcile the Saipov they met and the one they are now hearing about.

Those who knew him in Tashkent, Uzbekistan, and in at least three states he bounced between since coming to America, say they saw no warning signs of Saipov being radicalized.

Maybe an occasional outburst. A bit of a hothead. A little bit secretive here and there.

But no indication he would ever carefully plan a terror attack in the name of ISIS.

"I don't remember him being aggressive, or having bad attitude with others. Overall, I remember him positive," Kadirova says. "Whatever happened, that happened after he moved to USA. When I saw him on news, I couldn't believe that it [was him.] I hardly recognized him."

A 'peaceful' upbringing

Saipov lived and attended private school in Tashkent, Uzbekistan, before coming to United States.

Saipov grew up in Uzbekistan's capital city of Tashkent, living with his parents until 2006. He lived in an apartment there with his three sisters, neighbors say. Saipov's family is remembered fondly.

"They were known as a normal, secular and peaceful family," one neighbor in town says. "No radical religious views, or at least they didn't show any."

They were "a good family," a resident who used to live across the hall says. Both residents say after 2006, the family bought a private home, which they thought meant the family was financiall well off.

The young man never provoked suspicions, neighbors say. They told authorities he kept a low profile and was friendly, according to an e-mail from the Uzbekistan Embassy.

His parents preached traditional Islam, according to the Uzbeki government. Neighbors say they didn't attend mosque and were secular. And nobody in town noticed any communication with extremist groups.

Residents in town are now concerned that the stigma of Saipov will somehow connect them to the incident. They don't want to say much. Police and security services have swarmed the area.

Aggression, a family and a disappearance

Saipov began to put down roots of his own in Stow, Ohio, after arriving in the United States on the diversity visa.

The suburb just north of Akron, Ohio, is where he would start his first business and eventually get married. Mirrakhmat Muminov remembers the first time he saw Saipov in the town where about 30 other Uzbek families lived.

But Muminov says Saipov lived a bit removed from the town's Uzbek community.

Both men were in the trucking industry. Saipov registered his company Sayf Motors Inc. in Ohio in 2011. And at one point he worked for Muminov as a truck driver. It was only for a couple of months.

"He was fired because of [a] customer quality issue," Muminov says. "Someone complained about him."

While Muminov says there were some disagreements between Saipov and the community, he made at least one meaningful connection in town. In 2013, he married a fellow Uzbek also from his hometown of Tashkent. He was 25. Nozima Odilova was 19. They were married in Cuyahoga Falls, Ohio. The marriage license listed him as a truck driver.

Saipov registered a motor carrier business, Bright Auto LLC, in Ohio that same year.

Saipov's three years in Ohio would be relatively mundane. But he certainly left an impression on Muminov, who describes himself as an employer and acquaintance of Saipov.

There was something a little off about him, Muminov says.

He was an "aggressive man." Some bad habits. He seemed nervous. Small things seemed to nag at him a bit deeper. Saipov could yell at people for no reason, Muminov says.

It was as if Saipov was always "swimming against the rules."

"I can describe him like this nervous, young man with some monsters maybe inside his mind," Muminov says.

He never showed signs of radicalization, Muminov says.

There were rumblings about financial trouble and elements of depression, he told Radio Free Europe.

Saipov's time in Stow ended quickly. He moved in a rush, Muminov says. There was no goodbye.

"He just take everything in one day and he disappear. He didn't say a word."

A man of few words

Sayfullo Saipov lived in this apartment complex in Tampa, Florida, before moving to New Jersey.

Saipov made his way south, eventually ending up living with his wife and three kids in an apartment complex in Tampa, Florida.

He and his family mostly kept to themselves, neighbors say. A 59-year-old Egyptian woman says Saipov's wife wore a niqab, a traditional Muslim veil that left only her eyes showing.

The only words she ever exchanged with Saipov were to say "Salam-Alaikum," wishing each other a good morning.

It wasn't out of the ordinary, she says. Most people here kept to themselves. And many didn't stay for too long.

The family didn't socialize often. Neighbor Melissa Mathews has lived in the complex three years and only saw them socialize once. There was a barbecue on Saipov's back patio. Saipov's young children sometimes played in the community pool.

Saipov seemed to have regular hours -- as if he had a job, Mathews says.

It is unclear how much of Saipov's time was on the road as a trucker. But he began racking up traffic violations. He already had a ticket from December 2011 in Iowa for not keeping his commercial driving log up to date. In April 2014, he was cited for missing a reflective device on the rear of his tractor-trailer cab, cracks on his windshield and oil on the front of his car hauler.

Then in December 2015, he was ticketed for an equipment violation in Missouri. His tractor-trailer had cracks in the brake lining, according to a statement obtained by CNN affiliate KMBC . He had the option of paying a $129.50 fine for the offense. Or he could tell officials he wanted to plead not guilty. He did neither, the prosecutor said. So a warrant was issued for his arrest. He was taken into custody in Missouri in 2016 and posted a $200 bond.

Saipov's Tampa neighbors say he left town suddenly.

One day the family was just gone, Mathews says.

The alleged plot comes into focus

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The last known move Saipov and his family made was north to New Jersey about a year and half ago.

In just a few months, he would become inspired to carry out a deadly attack in the United States, authorities allege. Saipov watched ISIS videos on his cellphone, according to court documents.

At the same time, he was establishing himself in his Paterson, New Jersey, neighborhood.

One neighbor even viewed him as somewhat of a peacemaker, though he didn't extensively interact with him.

Carlos Batista was riding his dirt bike in the neighborhood about six months ago.

Saipov's friends complained it was too loud and things got a little testy. But Saipov stepped in and "calmed everything down," Batista says.

While living in Paterson, Saipov began driving for Uber. He passed his last background check for the company in July 2017. There are no reports of any complaints from customers, the company says.

It was about one month later that Saipov made the decision to use a truck in the attack, authorities say.

Authorities say Saipov, in a hospital bed after being shot by police, shared details of what he did in the month leading up to the attack.

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They say he told them he chose a truck as his weapon to "inflict maximum damage." He said he was motivated in particular by a video in which ISIS leader Abu Bakr al-Baghdadi asked what Muslims in America and around the world were doing to respond to Muslims being killed in Iraq, court records state.

Saipov began narrowing in on the specifics of the attack in early October. His internet searches focused on details about Halloween in New York and truck rentals, according to court documents.

Nine days before the attack, Saipov told authorities he rented a truck "so he could practice making turns with the truck in advance of the attack."

Neighbors in Paterson had no reason to question the Home Depot truck in the community, even though they never saw it being used with tools or for any work.

The day of the attack, Saipov traveled to a Home Depot and rented a truck under his name for two hours. He never intended to bring it back, according to court documents. He thought about displaying ISIS flags on the truck, but decided against it, so it didn't attract attention. His plan was to drive the truck into pedestrians on the West Side Highway, and continue all the way to the Brooklyn Bridge, according to court documents.

Saipov killed eight people and injured more than a dozen in the process, police said. The attack ended when the truck crashed into a school bus.

Witnesses said the driver exited the truck yelling "Allahu Akbar." He carried a paintball gun and a pellet gun, police said, and left behind a bag of knives and a handwritten note in Arabic stating that the Islamic State would endure. Saipov was shot by police and taken to the hospital.

Authorities say they found a trove of videos and pictures related to ISIS on Saipov's phone: 90 videos full of propaganda, beheadings, instructions on explosives and about 3,800 images, including the ISIS flag and images of the ISIS leader.

On Tuesday, from his hospital bed, Saipov seemed to show no remorse, authorities said.

He asked to display an ISIS flag in his hospital room, court documents show.

On Wednesday he was wheeled into a federal courtroom to face the charges against him: providing material support to a terrorist organization and violence and destruction of motor vehicles. He entered no plea.

Meanwhile, friends and relatives were baffled by what they've learned.

Saipov's mother-in-law lives in a Brooklyn neighborhood that's home to Uzbek immigrants. When approached in the lobby of her apartment building on Tuesday, she said she was in shock.

"I don't know what happened," she said.