I don't really think of this killer as a criminal mastermind. A significant portion of his remaining loose probably has more to do with his being lucky rather than skill. If he tried to do this again something could very likely go against him. But you're right, he is certainly no idiot. To the best of our knowledge he hasn't shown up back on the scene. Most likely he hasn't bragged or confessed to anyone. (There is a slight chance he has, maybe while drunk or high, or the person hearing it fears for their life, but I doubt it.).
This guy, who has been unapprehended for almost five years, is anything but an idiot.
Or, if he is, this drops the bar for LE involved in the case even lower, and I don’t want to think so. They are local, rural, maybe average-level, but no worse than that.
Personally, I think they were inexperienced in such sorts of crime. And the murderer, already too experienced. Also, sadly, there are too many killers like this roaming around.
As someone has recently alluded to, this massive publicity to solve the murders may be working against us. Somewhere he may be sitting back getting off on all this and still getting some personal mileage out of it. I think back to the country comedian Ron White and picture him in his shorts and T-shirt, sitting in his beanbag chair, eating Cheetos and following all this on his laptop. When in reality, what he really is is just some low-life dirtbag who has crawled into his hole to hide.