While there are still many investigative leads to follow up on, top NYPD officials say they are now getting a clearer picture of Luigi Mangione.

Marked shell casings from the assassination scene match the gun found on the suspect. His fingerprints match some key items investigators found nearby. And he was arrested this week – after going silent from his mom and friends for months – with a fake ID and a handwritten “claim of responsibility” referencing the crime site.

Luigi Mangione was arrested on gun charges in Pennsylvania and faces a murder charge in New York for the death of UnitedHealthcare CEO Brian Thompson.