I have a theory about one of the triggers of CW's homicidal rage. (A contributing factor.) MOO.
SW appears to have been a very high-energy person. Go, go, go! Lists! Organization. Motivation.
CW was described as "shy Chris." I bet he was lower energy.
As a low energy person myself, I find it completely exhausting to be around high energy people. And it is frustrating, because maybe you just want to do a whole lot of nothing (like hanging out on websleuths for hours at a time, for instance). But the high-energy wants to get stuff done---like NOW! Not tomorrow, not in a few minutes, drop everything you are doing and help me with this _____. Or give the kids a bath. (And it's like, "ugh, I just sat down and I'm writing this comment, can't you just leave me alone for ... ten minutes?? (sigh) Yes, this is a message board. It's people talking about crimes.)
So CW was alone at home for five weeks. His wife would text him and give him lists to make sure he stayed on top of things, but he could ignore her texts pretty easily when she is 1500 miles away.
And he got used to it. And he liked it.
And then she came back.
And she started in, "why didn't you do this? and why didn't you do that? Why didn't you eat all the meals I made for you? I can see dust on top of the refrigerator? Did you take the dog to the vet like I asked Why is there beer in the fridge??" And she wanted him to do the stuff again. And he didn't want to do the stuff right then. And geez, can we give it a rest just for a FEW MINUTES?!?!?!???
So three days later she goes on another business trip. But she makes sure to leave him a very detailed list of the things she wanted him to do. And grrrrrr....
And pretty soon it's. . . . . "HERE'S JOHNNY!!!"