I'm a little surpised by the arrest only because I had gone away from my initial thoughts and started to feel sorry for the husband.
My first thought were related to the income of a soldier, that huge four bedroom house with no children and the fact that the much younger wife had probably changed a lot since the time of marriage ... that is, she completed the dental hygiene training and probably made a lot of new friends through both work and the medieval club between the ages of 20 and 28.
I wondered if she wanted a bigger better house, and whether he wanted to keep her happy even if it meant that they would financially over-extended (I don't know that they were, just speculation). I wondered if he wanted children and she kept putting it off. I wondered if she was flirting with someone when they were out with friends (upsetting her husband) and I wondered if, now that she had the financial assets, she was thinking about leaving her husband.
I don't know whether any of this is possible, but when a wife is murdered and the husband says that "she went for a late night drive alone", I have to wonder if there was an argument that led to murder. If there was an argument, I want to look at the known facts and try to understand where there could have been problems. The first red flag for me was the possibility of financial problems for the husband.