Investigators continued Thursday to investigate the 29-year-old Uzbek immigrant charged with the New York truck attack, poring over his communications to see whether he had any help before the deadly rampage, while President Donald Trump publicly weighed in on the federal prosecution of the suspect.
New York police officials say that the attacker appears to have self-radicalized and that it does not appear anyone else was involved, though they said that continues to be a key question in the international investigation launched after the Halloween attack in Lower Manhattan killed eight people and wounded a dozen others.
Authorities are trying to determine whether Sayfullo Saipov, who was charged Wednesday with providing support to a terrorist group, only drew inspiration from the Islamic State and its calls for adherents to attack using vehicles, or whether he was enabled in some way, which so far does not seem to be the case, officials said.
The man the FBI said it was seeking as a person of interest in the New York truck attack has condemned the plot and says it was "not from our religion."
The man, Mukhammadzoir Kadirov, has not been detained or arrested. On Wednesday, the FBI released a poster saying it was looking for Kadirov, only to announce less than 90 minutes later that it had found him. A law enforcement official said Kadirov was a friend of Saipov's and may not have any role in the case.
On Thursday, Kadirov released a statement to the Associated Press through a source in touch with his family. It reads: "It is so sad and unbelievable. This not from our religion. It is not acceptable. We as Muslims completely reject this kind of actions. No human being who has a heart can do this."
A key difference in this case compared with past attacks is that Saipov, who was shot by a police officer after crashing his truck into a school bus, was taken into custody alive.
"When you capture a live terrorist, you have the ability to question that person and you're able to glean a lot about those things," John Miller, the deputy commissioner of intelligence and counterterrorism with the New York City Police Department, said Thursday on CBS This Morning. "Were they part of a larger network? Is this something bigger? Were they acting alone?"
Saipov could also offer information to authorities helpful beyond his case, because a suspected terrorist in custody also lets investigators delve more deeply into "the arc of their radicalization," Miller said.
"What we're seeing today is, in the United States, a great deal of that is just done online," he said.
In court documents, authorities depicted Saipov as a man who plotted carefully and was proud of the carnage inflicted upon pedestrians and bicyclists Tuesday afternoon.
Officials said Saipov told them he wanted to kill as many people as he could, picking Halloween because he thought more people would be outside, according to the criminal complaint.
Trump tweeted hours after Saipov was charged that he "SHOULD GET DEATH PENALTY!" On Thursday, Trump backed away from his suggestion a day earlier that he could send Saipov to the U.S. military prison at Guantanamo Bay, Cuba, writing that there was "something appropriate about keeping him in the home of the horrible crime he committed."