Once Mangione is extradited, he is expected to be charged with first-degree premeditated murder, which is rarely charged unless an officer has been killed, according to the New York Police Department. The prosecution has the final say on all charges.
Here's a look at the evidence authorities say they've collected against Mangione so far.
His notebook entries
Authorities found a spiral notebook was from Mangione when he was arrested, two law enforcement sources told CBS News. They said Mangione wrote that he had considered using a bomb but chose a shooting instead because it was more targeted and would avoid endangering innocent people.
Mangione did not incriminate himself in his statements to investigators, police said. But the investigators describe the tip as Mangione's confession of responsibilitysources told CBS News.
Some of the notes in his notebook expressed contempt for the American economy and particularly the health care system, according to the NYPD. This is consistent with the investigators' working theory the possible motive of the suspect for targeting Thompson, which represents blatant hostility to the healthcare industry.
According to police, Mangione suffered a serious back injury in 2023, which led to a visit to the emergency room and surgery to add screws to his spine. He posted pictures of spinal X-rays on his social media.
Fingerprints and DNA
Authorities said they were able to identify Mangione as a suspect in Thompson's killing relatively quickly based on forensic evidence that allegedly linked him to the crime.
“We have DNA,” NYPD Chief Detective Joseph Kenny said as the investigation began. “We have fingerprints that are being processed.”
Police took Mangione's fingerprints when they took him to prison in Pennsylvania, and those prints matched those left on a water bottle and a KIND bar found near the crime scene, NYPD Commissioner Jessica Tisch said on Wednesday. The bottle and protein bar packaging were collected near the Starbucks where the suspect was seen on surveillance video Minutes before the shooting.
Mangione also goes well with prints found on a cell phone Recovered near the construction site, police said.
The weapon
police said a 3D printed weapon and silencer found in Mangione's backpack at the time of his arrest matched the weapon used to shoot and kill Thompson, and that they linked the weapon in his backpack to three spent 9mm shell casings found at the crime scene were found. This type of firearm, sometimes called a “ghost gun,” can be made at home using a 3D printer and does not have a serial number, making it difficult to trace. (Not all ghost guns are illegal and not all firearms require a serial number.)
The gun in Mangione's possession contained a loaded Glock magazine with six 9mm cartridges and a 3D-printed silencer, according to the criminal complaint filed in Pennsylvania.
Early in the investigation into Thompson's death, NYPD sources told CBS News that several words were meticulous written with Sharpie on bullet casings and bullets recovered from the crime scene. The words were “delay,” “deny” and possibly “shut down,” which investigators believed could refer to the “Ds of insurance” coined by critics of the industry. The original alliterative list — “delay, deny, defend” — comments on the tactics that insurance company opponents say they use to deny claims.
Face mask, clothing, fake IDs
When he was arrested, items of clothing, including a face mask, and fake identification cards similar to those used by the shooter were found in Mangione's possession, police said.
After the shooting, surveillance video and images of the suspect spread, capturing the moment of the shooting as well as his previous visits to a Starbucks store in Midtown and the front desk of an Upper West Side hostel. Authorities believe he remained. The suspect's full face was only visible on surveillance footage from the hostel. Other images and videos showed him wearing a black face mask and a hoodie.
Mangione had a fake New Jersey driver's license on him when he was taken into custody in Pennsylvania, which matched what police said was the fake ID he used to check into that New York hostel. According to police, that driver's license was among several fake IDs discovered in his possession. He also had a United States passport, $8,000 in cash and a handwritten note.
Mangione was reported missing
Mangione's mother reported her son missing to San Francisco police in the days before the Dec. 4 shooting, a person familiar with the investigation told CBS News.
She filed this report even though Mangione's friends and family appeared to be even more concerned about his whereabouts and well-being. Posts tagging him on social media suggested that Mangione had lost touch with people who were once closer to him.
Pat Milton, John Doyle, Marcia Kramer, Dick Brennan and Anna Schecter contributed to this report.
