I don't believe John committed the murder since the crime scene was remarkably sloppy. There are two main pieces of evidence that bring me to this conclusion the location of her blouse and her bruises. Even John is her abusive ex husband he still a cop who is familiarized with the knowledge of crime scene protocol and arson crimes the sloppiness of the crime illustrates lack of knowledge. He would know that investigators would find the blouse when doing a search of the house. Basic police education would provide him with the knowledge that strangulation and bruises would be distinguishable on burned
