Sayfullo Saipov, who has been charged with killing eight people in a vehicle attack on the West Side of Manhattan on Tuesday, was interviewed in 2015 by federal agents about possible ties to suspected terrorists but a case was never opened against him, law enforcement officials tell ABC News.

Saipov was listed as a “point of contact” for two men whose were listed in a Department of Homeland Security counterterrorism database and later overstayed their tourist visas, a federal official told ABC News. One was flagged after arriving from a so-called “threat country,” while the other vanished and was being actively sought by federal agents as a “suspected terrorist.” An official told ABC News that the FBI has since located him and he is not believed to have been involved in Tuesday’s attack.

Speaking on Wednesday, President Donald Trump noted that Saipov had served as the “point of contact” for 23 people. A source confirmed that number to ABC News but said it is unclear if those people are "immediate family members, distant family members, or friends.” Only those two men, however, were listed in the database.

PHOTO: Sayfullo Saipov, the suspect in the truck attack that killed eight people in New York on Oct. 31, 2017, in an undated photo from the St. Charles County Dept. of Corrections in Missouri. (St. Charles County Dept. of Corrections via AFP/Getty Images) More

A Department of Homeland Security spokesman said that its law enforcement agencies -- Customs and Border Protection, Immigration and Customs Enforcement and Homeland Security Investigations -- "did not interview Saipov in 2015."

Saipov, 29, is originally from Tashkent, the capital city of Uzbekistan. A former neighbor of Saipov’s in Tashkent, who did not want to be identified, told ABC News today that she remembers Saipov’s family as modest and secular and described Saipov as “a normal young man” when he lived there.

“The family was normal, modern, wearing tight pants, no scarfs,” she said. “They did not go to the mosque.”

According to a statement released by Uzbekistan's embassy in Washington, Saipov graduated from college, worked as an accountant for a hotel and had no previous criminal record while living in Tashkent.

“Neighbors in makhalla (local community in Uzbekistan) described Saipov quite positively: according to them, he did not provoke any suspicions, always kept a low profile and used to be friendly in relation with others,” the statement reads. “He was brought up in a good family environment. His parents preached traditional Islam and have never been noticed in communications with any extremist groups.”

PHOTO: The apartment in Tashkent, Uzbekistan, where the suspect in the terrorist attack in New York, Sayfullo Saipov lived between 1996-2006, Nov. 1, 2017. (ABC News) More

He entered the United States through a Diversity Visa Program lottery in 2010, making him a legal permanent resident of the United States upon arrival. He has lived in Ohio, Florida and, most recently, Paterson, N.J. with his wife, Nozima, and three children, who were escorted from the residence by the FBI as federal agents and evidence technicians were gathering evidence on Wednesday.

On Wednesday, however, Trump took aim at the program that allowed Saipov to gain entry to the country on Twitter, calling it a “Chuck Schumer beauty” and vowing to replace it with “merit based immigration,” but the accused attacker appears to have been radicalized from within the United States

Authorities say Saipov, who was shot by police following the attack, told them from his hospital bed that he was proud of what he had done. Investigators searching Saipov’s online activities have found social media links to people who are or were subjects of terror investigations. And authorities say Saipov claimed in a handwritten note found near his truck that he carried out Tuesday’s attack on behalf of the so-called Islamic State, or ISIS.

PHOTO: Crime scene investigators walk along the west side bike path in lower Manhattan, New York, Nov. 1, 2017, a day after a truck plowed down the path pedestrians and cyclists. (Seth Wenig/AP) More

Story continues