Well, I disagree with this. I lived in South Africa when apartheid was coming to an end and there was a lot of unrest and uneasiness. Just a difficult political time and a lot of people were, rightly, angry. But it was dangerous. My parents both had guns; both well trained in them. If someone DID break in, they would shoot and they would shoot to kill. There is nothing immoral about that. It can be a very dangerous country, and if you have an intruder then shooting to kill is not morally repugnant.
In this case though, it is a moot point. I don’t believe his intruder story. He murdered her in cold blood. This was not an accidental mistaken identity, he wasn’t shooting in self defence. He is just a murdered so yes, HE deserves nothing. But you cannot apply that to anyone who has ever shot bullets towards an intruder.