I already debated this in the thread about this same subject. I think his decision to fire bullets in his own garage was extremely stupid, but at the same time in the article which discussed the incident mentioned that the police saw no marks on the victim's neck and that she was uncooperative.
If more concrete evidence comes out saying that he did some terrible things to his gf then I agree that measures need to be taken, but right now I don't think it would be justified with the information available to us.