I was responding to
@Puzzles8 as the thread changed and I lost my post. I agree with your theory
@rabidstoat , that steroids may have been a part of his aggression. Diet. I think he dedicated that summer to not coming back to school being the heavy kid that he was. New Year New Me. We then see that he gets started in boxing and running. His eating habits drastically change. This fella is lean and strong. His still very rigid with his eating. Possibly to the point of an eating disorder, but not anorexia. He seemed to have made a pivot over that summer, and then possibly started abusing drugs, and possibly drinking too. He represented that he did. I think it's entirely possible he started abusing steroids, and very likely one or more others. But those eyes. Something is just not right. Even a friend or two noted his eyes.
I thought this guy would have to be athletic. I was thinking upper body strength would have to be a factor. Possibly had on shorts and a college t., underneath coveralls, threw the coveralls, shoes, and knife in a bag, Ditches his coveralls and shoes in a dumpster or lake along the way. There are two routes he could have taken, both take about the same time. He'd be just another white sedan traveling home. He could've told his mother he was heading home the day before. He's young. He could drive 18 hours, maybe more, especially on an adrenaline rush, and he'd arrive about right on time. If he's truly a psychopath or some other path, he learned how to blend a very long time ago. He's a chameleon. IF he's a true psychopath, he knows right from wrong, so insanity would be out the window. JM2 All psychopaths don't go around murdering people. They adapt. IANAPsychiatrist, I just play one from my armchair. Seriously though, in every picture, the eyes have it.