Luigi Mangione has been charged with first degree murder over the killing of healthcare CEO Brian Thompson last month, New York District Attorney Alvin Bragg said on Tuesday.
Mr Mangione has been indicted on one charge of first-degree murder, as well as two counts of second-degree murder, one of which is charged as killing as an act of "terrorism", Bragg said.
Announcing the charges, Bragg called the shooting a "frightening, well-planned and targeted murder".
Mr Mangione is scheduled to appear for a court hearing on 19 December over whether he will be extradited to New York on the charges, according to the BBC's media partner CBS News.
The extradition proceeding will be held the same day he will sit for preliminary proceedings for gun-related charges in Pennsylvania.
Mr Mangione was arrested at a McDonalds in Altoona, Pennsylvania, with a so-called "ghost gun" and fake ID, police said, five days after he allegedly shot and killed healthcare CEO Brian Thompson on 4 December.
His lawyer, Thomas Dickey, has said he plans to fight the extradition and maintains he has not seen evidence that links Mr Mangione's gun with the crime.
New York prosecutors began to share evidence in their case against Mr Mangione with a grand jury last week.
Manhattan District Attorney Alvin Bragg has suggested that Mr Mangione might waive extradition which means his arrival to New York would be imminent, according to CBS News.
If extradited, the 26-year-old is likely to be held at Riker's Island or another New York prison.
The evidence against Mr Mangione includes a positive match between his fingerprints and those discovered at the scene of the crime, NYPD Commissioner Jessica Tisch has said.
In addition to the ghost gun - a gun assembled from untraceable parts - and fake ID, police said they also found a passport and a handwritten document that indicated "motivation and mindset" on Mr Mangione during his arrest.
He was formally charged in Pennsylvania with forgery, carrying firearms without a licence, tampering with records or identification, possessing instruments of crime and providing a false identification to police.
While Mr Mangione awaits his fate in the New York court system, he remains under maximum security at Huntingdon State Correctional Institution in Huntingdon County, Pennsylvania.
He has been denied bail.
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