Fingerprints From Scene of CEO Brian Thompson's Killing Match Murder Suspect Luigi Mangione: Source

Fingerprints recovered from the scene of UnitedHealthcare CEO Brian Thompson’s killing in New York City match those of murder suspect Luigi Mangione, a law enforcement source tells PEOPLE.

Shell casings found at the site of the shooting match Luigi’s fingerprints. Along with a water bottle, and a KIND bar near the scene, the source said.

Mangione, 26, is charged in New York with second-degree murder, firearm possession, and forgery, per an arrest warrant filed by the Manhattan District Attorney’s office.

He was arrested on Monday, Dec. 9 after being recognized at a McDonald’s in Altoona, Pa., where an employee called police.

After Mangione was arrested in Altoona, authorities say they discovered a 9mm “ghost gun” — similar to that used to shoot Thompson — in his possession, along with multiple fake IDs. A police source tells PEOPLE he also carried a three-page “manifesto” critical of the health insurance industry.

Mangione’s defense attorney Thomas Dickey said on Good Morning America on Wednesday, Dec. 11 that he’s seen “zero evidence tying Mangione to the murder.”

“As I indicated yesterday, I have not been made aware of any evidence that links the gun that was found on his person to the crime,” he said. “These are things we’re looking to see. Yesterday was fast, today’s another day. We’re looking forward to beginning our inquiry as to what evidence may or may not be out there.”

The Ivy league graduate also faces charges in Pennsylvania for carrying a weapon and showing a fake ID to a police officer. He was arraigned in a courthouse near Altoona on Tuesday, Dec. 10, and was denied bail. His lawyer also indicated he would fight attempts to extradite him to New York to face murder charges. Mangione has not yet entered a plea.

As he was being taken into court on Tuesday, Mangione appeared to yell a message to members of the media.

“It’s completely out of touch! It’s an insult to the intelligence of the American people!,” Mangione appeared to yell in a video captured by news cameras. It’s not clear what Mangione was referring to.

The murder charge is related to the Dec. 4 killing of Thompson, 50, the chief executive of one of America’ largest health insurers.

The CEO was gunned down in front of the New York Hilton Midtown hotel in Manhattan where he and other executives were set to gather for a corporate investor meeting. The father of two was pronounced dead at a local hospital a short time later.

Bullet casings found at the crime scene reportedly had the words “deny,” “defend” and “depose” engraved on them — a possible reference to “deny, delay, defend,” a phrase used to describe insurance industry tactics for dodging claims.

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Authorities believe Mangione, who allegedly fled the scene on an bicycle through Central Park before escaping the city, deliberately targeted Thompson. In the alleged manifesto, Mangione claims he acted alone.

Several reports have alleged Mangione has been dealing with “debilitating” back pain in recent years with friends and family losing contact with him in recent months.