Has no one considered that he was smart?
Follow along here for a second...
You’re planning on killing a cop at a barracks. You know that eventually they’re going to figure out who you are and consequently your vehicle will become radioactive, so get ahead of it. You dump the vehicle in a manner that appears as if you accidentally got it stuck. Just to be sure, leave enough clues, like a SSN or spent cartridges.
You then hop into your getaway vehicle(or maybe a motorcycle) and go in the opposite direction knowing the cops are going to focus on the wrong spot.
Once he’s clear of PA, the heat goes down significantly.
The other alternative would be that he suicides in an old mine or something and they’ll never find him.
I agree to some extent with your assessment, but I think in some circles he might be considered a hero and is being sheltered well out of the area.