Perhaps you should review the post I was responding to, and in fact the entire thread up until my post. And the remainder of the thread after that, as a matter of fact - I think you'll find that the vast majority of posts speculating about a motive are basically attempts to find some way in which this was the victim's fault. Strange how you don't call them out as well. Apparently my sin is pointing out that there are other possibilities as well, and thereby not following the herd. So be it.
My sin was ONLY reading your post. I apologize.
After she's lawyered up, I fully expect to read that a) he was having an affair with an unnamed woman, b) he beat his wife, c) he beat his kids, d) he molested his kids, or e) he admitted to being gay.
Or possibly some combination of one or more of the above, with a problem with drugs, gambling, or prostitution thrown in for good measure.