Three shell casings recovered outside the Manhattan hotel where UnitedHealthcare CEO Brian Thompson was fatally shot match the untraceable gun allegedly found on the suspect, Luigi Mangione when he was arrested in Pennsylvania, officials in New York said on Wednesday.

Fingerprints recovered from a water bottle and a Kind bar near the crime scene have also been matched to Mangione, NYPD Police Commissioner Jessica Tisch said Wednesday.

Mangione was apprehended in Altoona, Pennsylvania, on Monday after nearly one week on the run.

A judge in Pennsylvania ordered Mangione held without bail on Tuesday. In Pennsylvania he faces charges including allegedly possessing an untraceable ghost gun.

Mangione plans to challenge his extradition to New York, where he faces charges including second-degree murder.

"He has constitutional rights and that's what he's doing" in challenging the interstate transfer, defense attorney Thomas Dickey told reporters on Tuesday.

This is a developing story. Please check back for updates.