Very sad news; it's part of todays world, you go to the woods expecting solitude and find crime. There are too many meth heads hanging out in the woods cooking that crap. No telling who or what you will run across nowadays, I always have a concealed handgun (licensed) on me when out woods-bumming.
I hope they are able to catch the scumbag who did this to these old men. Sounds like the robber could have just walked away from his victims without shooting them.