This is starting to remind me of an incident in Cortez, Colorado about ten years ago. A couple of locals stole a water truck and were heading to the Indian Casino, apparently to rob it, when a police car noticed them. They shot and killed the police officer, dropped the plan to rob the casino, and went straight to their getaway plan. They were well trained in camping and survival skills, and they dissappeared into some rugged canyonland. One of the largest manhunts in Colorado began and lasted months. One died in a shootout a few days later, but the other one vanished. That is, until one day years later, when hunters found his dehydrated corpse hidden in a canyon. He had shot himself within a few days of the shooting.
Living on the run in the wilderness takes a certain kind of person. I have camped in that area in Colorado, and it is difficult to be there alone. You might think you are getting away from your problems, but your problems follow you into the wilderness, where you can be alone with them day after day until they consume you.
I think his body will be found in the wilderness, a suicide.