I see this murderer as an employed man in a stereotypically male profession…one which has some risk, where hand tools are used, and where he does not have to interact often with others. I also see him as able to move around geographically a fair amount. He is accustomed to uncomfortable circumstances. I am thinking about some sort of skilled labor, like welding, tree trimming, roofing. I can’t see him holding a job for very much longer than some months because he has obvious disdain for other people. He may even prefer solitary work or third shift to minimize his interactions. He’s reliable, experienced, and good at what he does. He’s probably been at it for some time, maybe placing him in his thirties.