FWIW, I was curious what the guy was majoring in at Washington State, because he seemed to have made NO mistakes - as if he knew exactly what to do/ had done all this many times before. In other words, the killer seemed to have taken a page from Ted Bundy and somehow knew how to commit murder while leaving absolutely no good evidence. How could he be that smooth?
It turns out the suspect was a graduate student in "criminology", so I'd say my suspicion and my sleuth was well founded!. Bundy had a similar background, majoring in law and working for a police department (so he knew how the police would approach the investigations).
http://www.nytimes.com/live/2022/12/30/us/idaho-murders-arrest
Unfortunately for him, they apparently DID find some of his DNA on site. Maybe he was weak in one subject? In his booking photo, the guy looks pretty unconcerned with his situation. Cool and happy as a Bundy, you might say?