President Donald Trump called Thursday for the man charged over the New York truck attack to be executed, as a picture emerged of an Islamic State group sympathizer radicalized after struggling with life in America.
Trump had said he was considering sending Sayfullo Saipov, 29, to the military's notorious Guantanamo Bay detention center, but backed off the idea in a blast of early morning tweets calling for the death penalty.
"Would love to send the NYC terrorist to Guantanamo but statistically that process takes much longer than going through the Federal system," Trump tweeted.
"There is also something appropriate about keeping him in the home of the horrible crime he committed. Should move fast. DEATH PENALTY!"
Saipov appeared in a New York courtroom Wednesday on terrorism charges one day after he allegedly drove a rented pickup truck down a mile-long stretch of bike path in Manhattan, where children and their parents were preparing to celebrate Halloween.
Eight people were killed, five of them friends from Argentina celebrating 30 years since their high school graduation.
Twelve other people were wounded in the worst attack in New York since the September 11, 2001 Al-Qaeda hijackings. It ended when police shot Saipov in the abdomen.
Federal prosecutors have announced two charges so far: provision of material support and resources to a designated foreign terrorist organization, and violence and destruction of motor vehicles.
The maximum punishment is life imprisonment, but attorneys could potentially seek the death penalty. A capital punishment case would be extremely rare in New York.
The charging document said Saipov, an Uber driver and father-of-three who emigrated in 2010, confessed to acting in the name of IS and "felt good about what he had done," even demanding to hang an IS flag in his hospital room.
He first planned an attack in the United States a year ago, before settling two months ago on a vehicle strike, choosing Halloween deliberately in a bid to kill as many people as possible, the complaint alleged.
"He appears to have followed almost exactly to a 'T' the instructions that ISIS has put out in its social media channels," New York police deputy commissioner for intelligence and counter-terrorism John Miller said.
He was allegedly found in possession of three knives and two cell phones contained thousands of IS propaganda images and dozens of videos that showed IS fighters killing prisoners.
The US president vowed to "get rid" of the lottery program that allowed Saipov to enter the country, seizing on the attack to further restrict immigration.
But an increasingly detailed picture emerged Thursday of a suspect who only radicalized after moving to the United States in March 2010, his ambitions thwarted, growing out a thick beard and reportedly developing a violent temper.
The Uzbek government said nothing suggested he had been an extremist at home. He is the fourth man with Uzbek-links tied to attacks overseas in less than a year.
"His parents followed traditional Islam and were never seen in connection with any extremist branches," said a statement on a government-linked information agency.
The New York Times reported that he was a university-educated accountant from a well-off family when he migrated to the United States with dreams of prospering.
He won the green card lottery and moved to Ohio, before eventually finding work as a trucker and marrying a fellow Uzbek immigrant.
But over the years, he ran up traffic infractions, lost jobs and an imam worried that he increasingly misinterpreted Islam, the Times said, before the family relocated to the New Jersey town of Paterson.
The West Side bike lane where the attack happened has now re-opened, allowing tourists and New Yorkers to cycle or stroll in unseasonably warm weather, past bouquets and an Argentinian football jersey in tribute to the victims.
Tedd Wright, 43, said he didn't think twice before taking the path on his way to work Thursday.
"Not in America... You're hit in the face. What are you gonna do?" he said. "We'll win by positivity. There's way more good people in the world than bad people."