The Uzbek immigrant accused of mowing people down along a bike path went on the deadly rental-truck rampage "in the name of Daesh" and planned it for weeks, closely following the terrorist group's online instructions, police said Wednesday.
Investigators, meanwhile, questioned Sayfullo Saipov in his hospital bed, working to extract information about the attack that killed eight people Tuesday near the World Trade Center memorial. Saipov, 29, was shot by a police officer after jumping from his Home Depot pickup.
He left behind knives and notes, handwritten in Arabic, that said in essence that Daesh, "would endure forever," said John Miller, deputy police commissioner for intelligence.
"He did this in the name of Daesh" and seems to have plotted it "for a number of weeks" and conducted reconnaissance, Miller said. "He appears to have followed, almost exactly to a T, the instructions that Daesh has put out."
Meanwhile, the U.S. government on unveiled a criminal complaint accusing Saipov in connection with the Oct. 31 truck attack, charging him with two counts, including providing material support to Daesh, and causing the deaths of pedestrians with a truck he had rented.
The complaint said Saipov waived his right against self-incrimination while in custody.
It also said he admitted to having been inspired by Daesh videos, choosing Halloween for the attack because he expected more people on the street, and having planned to proceed to the Brooklyn Bridge to strike more pedestrians.
The Federal Bureau of Investigation also said in a wanted poster issued on Wednesday that it was seeking a second Uzbek man, 32-year-old Mukhammadzoir Kadirov, for questioning.
In the past few years, the Daesh terrorist group has exhorted followers online to use vehicles, knives or other close-at-hand means of killing people in their home countries. England, France and Germany have all seen deadly vehicle attacks since mid-2016.
A November 2016 issue of the group's online magazine detailed features that an attack truck or van should have, suggested renting such a vehicle and recommended targeting crowded streets and outdoor gatherings, according to the SITE Intelligence Group, a militant-monitoring agency.
Carlos Batista, a neighbor of Saipov's in Paterson, New Jersey, said he had seen the suspect and two friends using the same model of rented truck several times in the past three weeks.
It was not clear whether Saipov had been on authorities' radar. Miller said Saipov had never been the subject of a criminal investigation but appears to have links to people who have been investigated.
In Tuesday's attack, Saipov drove his speeding truck for nearly a mile along a bike path, running down cyclists and pedestrians, then crashed into a school bus, authorities said. He was shot in the abdomen after he jumped out of the vehicle brandishing two air guns, one in each hand, they said.
In addition to those killed, 12 people were injured.
The aftermath took a political turn Wednesday when President Donald Trump slammed the visa lottery program that Saipov used to come to the U.S. in 2010. Trump called the program "a Chuck Schumer beauty," a reference to the Senate's top Democrat.
The program dates to 1990, when Republican President George H.W. Bush signed it as part of a bipartisan immigration bill. Trump called on Congress to eliminate it, saying, "We have to get much tougher, much smarter and less politically correct."
Schumer, who represents New York, said in a statement that he has always believed that immigration "is good for America," and he accused the president of "politicizing and dividing" the country.
New York Gov. Andrew Cuomo said Saipov appeared to have acted alone after becoming radicalized while in the U.S.
Assailants in a number of other recent extremist attacks around the world were found to have been "lone wolves" — inspired but not actually directed by Daesh. In some cases, they never even made contact with the group.
On the morning after the bloodshed, city leaders vowed New York would not be intimidated, and they commended New Yorkers for going ahead with Halloween festivities on Tuesday night.
They also said Sunday's New York City Marathon, with 50,000 participants and some 2 million spectators anticipated, will go on as scheduled.
"We will not be cowed. We will not be thrown off by anything," said Mayor Bill de Blasio.
While the mayor said there have been no credible threats of any additional attacks, police said they were adding more sniper teams, bomb-sniffing dogs, helicopters, sand-truck barricades and other security measures along the marathon route, in the subways and at other sites.
The attack killed five people from Argentina, one from Belgium and two Americans, authorities said. Nine people remained hospitalized in serious or critical condition, with injuries that included lost limbs and wounds to the head, chest and neck.
A roughly two-mile stretch of highway in lower Manhattan was shut down for the investigation. Authorities also converged on Saipov's New Jersey apartment building and a van in a parking lot at a New Jersey Home Depot.
Runners and cyclists who use the popular bike path were diverted from the crime scene by officers at barricades.
"It's the messed-up world we live in these days," said Dave Hartie, 57, who works in finance and rides his bike along the path every morning. "Part of me is surprised it doesn't happen more often."
The slight, bearded Saipov is a legal, permanent U.S. resident. He lived in Ohio and Florida before moving to New Jersey around June, authorities said.
Birth records show he and his wife had two daughters in Ohio, and a neighbor in New Jersey said they recently had a baby boy.
Saipov was a commercial truck driver in Ohio. More recently, he was an Uber driver.
In Ohio, Saipov was an argumentative young man whose career was falling apart and who was "not happy with his life," said Mirrakhmat Muminov, a fellow truck driver from heavily Muslim Uzbekistan.
Saipov lost his insurance on his truck after his rates shot up because of a few traffic tickets, and companies stopped hiring him, said Muminov, 38, of Stow, Ohio. Muminov said he heard from Saipov's friends that Saipov's truck engine blew a few months ago in New Jersey.
Muminov said Saipov would get into arguments with friends and family, tangling over even small things, such as going to a picnic with the Uzbek community.
"He had the habit of disagreeing with everybody," Muminov said.
He said he and Saipov would sometimes argue about politics and world affairs, including Israel and Palestine. He said Saipov never spoke about Daesh, but he could tell his friend held radical views.