Prosecutors reportedly began to share evidence in their case against Luigi Mangione, the man accused of killing UnitedHealthCare CEO Brian Thompson, with a grand jury on Thursday.
The Manhattan District Attorney’s Office hopes to move quickly in their effort to obtain an indictment in New York City where Mangione allegedly shot and killed Thompson on 4 December, according CBS News, the BBC’s US partner, reported.
Mr Mangione’s lawyer is continuing to fight his extradition from Pennsylvania – where the suspected shooter was arrested on gun-related charges – to New York.
The Manhattan District Attorney’s Office did not respond to a request for comment.
New York Governor Kathy Hochul said on Thursday that she is also working to get Mr Mangione back to her state from Pennsylvania “because that horrific attack occurred on our streets”.
“The people of our city deserve to have that sense of calm that this perpetrator has been caught and he will never see the light of day again,” she added.
But Mr Mangione’s lawyer, Thomas Dickey, has said he plans to fight the extradition and maintains he has not seen evidence that link Mr Mangione’s gun with the crime.
“A lot of guns look the same,” he said earlier this week on ABC News.
On Wednesday, however, police found a positive match between Mr Mangione’s fingerprints and those discovered at the scene of the crime, NYPD Commissioner Jessica Tisch said.
Investigators are also looking at how Mr Mangione travelled into and out of New York City. They initially believed that he had taken a bus out of the city, but they now suspect he may have taken the subway to Penn Station – where they suspect he may have caught a train to Pennsylvania.
While Mr Mangione awaits his fate in the New York court system, he remains in in his own cell under maximum security at Huntingdon State Correctional Institution in Huntingdon County, Pennsylvania.
He was denied bail at his hearing on Thursday.
His next court appearance is 30 December.