Yes. That makes lots of sense. I don't see him wanting to return to the crime scene, maybe to gawk at the reaction perhaps, from afar. I think he ran off because he knew people were going to look for Vanessa, and having the crime so close to her family's home, part of the thrill was the reaction, seeing people search and he outsmarting everyone, possibly. Then afterwards it dawned on him, maybe when the profiler spoke of him, that he messed up, leaving too much evidence behind, or not being able to cover for his injuries. Maybe he's stuck with a set of circumstances he can no longer control. You have me convinced he may not be that confident, after all, just a pathetic dweeb who for some moments feels empowered, significant, like a man, when he makes others suffer. So this may be a person who feels unaccomplished, passed over, not taken into account, maybe rejected even, but so tini small, that he needed to this and other things like it to feel good about himself.
IF with speculation he has done things before getting away with it, he could have had plenty of confidence. It is hard to determine , but if he messed up with this, maybe not so much now.