-- The man accused of ramming a truck into people on a New York City bike path placed a call immediately before he carried out the attack on Tuesday afternoon, a law enforcement official told ABC News.
The call was placed to Mukhammadzoir Kadirov, who is described by sources as a friend of suspected attacker Sayfullo Saipov. Kadirov is not being called a suspect.
The significance of the call Saipov made to Kadirov is not known.
The FBI had released a poster Wednesday asking for the public's help to find Kadirov when he initially could not be located. But, less than an hour after the poster went public, Assistant Director in Charge Bill Sweeney announced that agents were no longer looking for Kadirov.
At least eight people were killed in Tuesday's incident, which is being investigated as a terror attack, and another 12 were injured.
Saipov, 29, was allegedly "inspired" to commit the attack after watching ISIS videos on his cellphone and he "wanted to kill as many people as he could," according to a federal criminal complaint filed Wednesday by prosecutors in the U.S. District Court for the Southern District of New York.
“During the interview with law enforcement, Saipov requested to display ISIS’s flag in his hospital room and stated that he felt good about what he had done,” the complaint states.
Saipov allegedly rented the truck from a Home Depot in Passaic, New Jersey, Tuesday around 2 p.m. ET. He exited the bridge at 2:43 p.m. and drove southbound on the West Side Highway in New York City, according to license plate readers on the George Washington Bridge.
Shortly after 3 p.m., Saipov allegedly began plowing into cyclists and pedestrians on a bike path in lower Manhattan near West Houston Street and the West Side Highway. The suspect then drove south for about a mile, leaving behind strewn bodies and crumpled bicycles, police said.
Saipov was transported to a hospital for treatment and is expected to survive. Officials say he acted alone.
City officials announced Thursday that the transportation department would begin to install concrete blockers in 57 spots along the bike path lining the West Side Highway beginning at 59th Street and heading into lower Manhattan. This will prevent cars from accessing the path but allow bikes and joggers to do so, they said.
Two cellphones, a stun gun, a document with text in Arabic and English and a black bag containing three knives were recovered from the truck. Saipov allegedly admitted to writing the document and told authorities the cellphones belonged to him, according to the criminal complaint.
Saipov has a preliminary hearing scheduled for Nov. 15 at 10 a.m. ET.
"He did this in the name of ISIS, and along with the other items recovered at the scene was some notes that further indicate that," John Miller, NYPD deputy commissioner of intelligence and counterterrorism, said Wednesday morning. "He appears to have followed almost exactly to a 'T' the instructions that ISIS has put out in its social media channels before with instructions to their followers on how to carry out such an attack."
The green card came via a government program called the Diversity Visa Lottery, which hands out about 55,000 visas per year.
After entering the country, Saipov first lived in Ohio before moving to Tampa, Florida. He then moved to Paterson, New Jersey, where he has lived with his wife and three children for several years, according to law enforcement sources.
During an interview with law enforcement while in custody, Saipov allegedly revealed that he began planning an attack in the United States about a year ago. He allegedly decided to use a truck "to inflict maximum damage against civilians" and rented one prior to Tuesday's attack to "practice making turns" with the vehicle, according to the criminal complaint.
"Saipov planned to use the truck to strike pedestrians in the vicinity of the West Side Highway and then proceed to the Brooklyn Bridge to continue to strike pedestrians. Saipov wanted to kill as many people as he could," the complaint states. "Saipov wanted to display ISIS flags in the front and back of the truck during the attack, but decided against it because he did not want to draw attention to himself."
Saipov allegedly chose to carry out the attack on Halloween "because he believed there would be more civilians on the street for the holiday," the complaint states.
ABC News' Mark Crudele, Tara Fowler, Joshua Hoyos, Aaron Katersky, Josh Margolin, Mark Osborne and Emily Shapiro contributed to this report.