Well, "just a group of trees" was probably being too general. You'd want an area where you could get into and out of without being witnessed. If he took his shot outside of a vehicle, this would mean an inconspicuous place to park that's not too far from where he's going to shoot- otherwise he'll have to cross a lot of ground carrying his weapon. If he's got an AR-15 or an M16 from the Army, he could easily break it down into two smaller pieces and stuff it in a bag of some sort, but it would still look kind of suspicious. I'd reckon he picked his spot because it offered him enough seclusion for himself and his vehicle and allowed him to overwatch a good "kill zone" that he was sure to have good targets in.
Some way/somehow, this person has mentioned to do his deeds without being caught....even if he is 'hiding in plain sight'. I'm trying to think like a killer when I'm not one....I'm trying to think what a cold-blooded killer needs to cover his a$$....and I guess I find comfort that most of us *can't* think like a killer.
sorry.....I'm rambling and brainstorming....we live near the area and I'm wondering how long we can go on living like this. My girls are in school which is on Day 3 of modified lockdown....and they just want to be able to go out for recess someday. (if and when they catch this idiot, I'm all for letting the parents and kids take a whack at him!)