Mr. Mangione is in a Pennsylvania prison, where he has been formally charged with possession of an unlicensed firearm, forgery and providing false identification to police.
He was handcuffed at his wrists and ankles when he appeared in court Monday morning.
Mr. Mangione, dressed in jeans and a dark blue jersey, appeared calm during the hearing and occasionally looked around at attendees, including the media.
Last week’s shooting sparked a massive search, with New York City investigators deploying one of the world’s largest digital surveillance systems, police dogs, drones and divers to Central Park Lake to search for the attackers.
Investigators said discovering Mr. Mangione came as a complete surprise because his name had not been on the list of suspects before Monday.
It was ultimately a McDonald’s customer in Altoona who recognized the suspect from media reports and alerted employees. The employee reported it to the police.
When police arrived, Mr. Mangione showed them a fake New Jersey driver’s license with the name Mark Rosario on it, court documents said.
When the officer asked him if he had been to New York recently, he “became quiet and began shaking,” the criminal complaint added.
He gave his real name after being told he would be arrested if he lied about it, according to court documents.
When asked why he lied, he said, “I definitely shouldn’t have lied.”
After searching his backpack, police found a “ghost gun,” possibly 3D printed, and a magazine loaded with six rounds of 9mm ammunition.
Prosecutors said he had a U.S. passport and $10,000 in cash, $2,000 of it in foreign currency, but Mr. Mangione disputed the amounts in court.
