Extradition proceedings will be held on the same day he sits for a preliminary hearing on gun-related charges in Pennsylvania.
Mr. Mangione was arrested at a McDonalds in Altoona, Pa., with a so-called “ghost gun” and a fake ID, police said, five days after he allegedly shot and killed the health CEO, Brian Thompson, on Dec. 4.
His lawyer, Thomas Dickey, said he planned to fight extradition and argued he had seen no evidence linking Mr Mangione’s gun to the crime.
Last week, New York prosecutors began sharing evidence in their case against Mr. Mangione with a grand jury.
Manhattan District Attorney Alvin Bragg suggested Mr. Mangione might waive extradition, meaning his arrival in New York would be imminent, CBS News reported.
If extradited, the 26-year-old will likely be held at Rikers Island or another New York prison.
Evidence against Mr Mangione includes positive match between his fingerprints and those found at the crime scene, New York Police Commissioner Jessica Tisch said.
In addition to the ghost gun – a gun assembled from untraceable parts – and a fake ID, police said they also found a passport and a handwritten document indicating Mr Mangione’s “motivation and mindset” at the time of his arrest.
In Pennsylvania, he was charged with forgery, carrying a firearm without a license, falsifying records or identification, possession of instruments of crime and providing false documents to police.
While Mr. Mangione awaits his fate in the New York court system, he remains in maximum security at the Huntingdon State Correctional Facility in Huntingdon County, Pennsylvania.
He was denied bail.
