Police have made an arrest in the murder of UnitedHealthcare CEO Brian Thompson, according to an Associated Press report.

Police arrested 26-year-old Luigi Nicholas Mangione after getting a tip that he had been spotted at a Pennsylvania McDonald’s, the AP reported.

When arrested, Mangione was arrested with a weapon “consistent with” the gun used to kill Thompson Dec. 4, according to the AP.

“As of right now, the information from Altoona is that the gun appears to be a ‘ghost gun’ that may have been made on a 3D printer, capable of firing a 9mm round,” NYPD chief of detectives Joseph Kenny told reporters at a news briefing today.

Thompson was killed Dec. 4 outside the New York Hilton Hotel, which was hosting UnitedHealthcare’s annual investor conference. Police suspected that the attack specifically targeted Thompson.

New York Police Commissioner Jessica Tisch said that when arrested, Mangione had a handwritten document that “speaks to both his motivation and mindset,” the AP reported. Police said the document suggested that Mangione harbored “ill will toward corporate America.”

Mangione will face gun charges in Pennsylvania, Kenny told reporters.

“And at some point we’ll work out through extradition to bring him back to New York to face charges here, working with the Manhattan District Attorney’s Office,” he said.