A US man who was behind the wheel of the car that barrelled through pedestrians in Times Square told police he had been smoking marijuana laced with PCP, according to a criminal complaint.
Richard Rojas, 26, made his first court appearance on Friday, a day after he was arrested in what New York police call an intentional attack that killed an 18-year-old Michigan woman and injured 22 other people.
"He murdered in cold blood," Assistant District Attorney Harrison Schweiloch said during the brief proceeding.
Rojas did not enter a plea and was held without bail.
His next court appearance is May 24.
Rojas, who lived with his mother in the Bronx, is accused of driving his car from his home through Times Square on Thursday, then making a U-turn, steering his car onto a footpath and roaring back along it, ploughing through tourists for three blocks before crashing into protective barriers.
Photographers snapped pictures of a wild-eyed Rojas after he climbed from the wrecked car and ran through the street waving his arms.
After he was detained, he said he wanted to "kill them all" and police should have shot him to stop him, a prosecutor told the court.
Officials are awaiting toxicology results, though Rojas "had glassy eyes, slurred speech, and was unsteady", during his arrest.
The hallucinogenic drug PCP can cause users to become delusional, violent or suicidal, according to the National Drug Intelligence Center.
Three people were still in critical condition with serious head injuries.
Alyssa Elsman, of Portage, Michigan, was killed in the crash and her 13-year-old sister was among the injured.