Mangione was arrested five days after the killing at a McDonald’s restaurant in Altoona, Pennsylvania, around 370km from the crime scene, following a tip from a staff member.
In another significant ruling, Garnett rejected Mangione’s lawyers’ efforts to suppress as evidence the police search of a backpack recovered at the time of his arrest.
Inside, officers found a handgun, a silencer, a magazine with bullets wrapped in underwear and a red notebook described as a “manifesto”.
The defence argued the search breached legal standards.
Mangione has pleaded not guilty to the state and federal charges.
- AFP