reporter: according to the defense, it was jean tan who had the motive the motive to get rid of her bully husband, get the house, the business, the money. frankly, it put motive in jean tan s category more so than charlie. reporter: and whatever little forensic evidence was at the scene was, according to the defense, inconclusive. there was a fingerprint on one of the shell casings and on the box of ammunition. so what that means is that at some point charlie could ve loaded the gun. but it still doesn t make him pull the trigger. reporter: as the defense saw it, the mom did it theory even explained that odd email that charlie sent his frat brothers before the 911 call the email called showtime. the email implied that the story to come might not be the real one. it went on to say this the real truth will come out one day. and you re gonna know what really happened. one of the things that was always a question and always a concern of ours was, was charlie coveri