two years after diane kyne was murdered in her own bed, her son, kevin, stood trial for killing her. the courthouse every day, still feeling the loss of his wife. >> she was everything i'd ever dreamed of in a lady. we were going to spend the rest of our lives together. >> sheriff's office. >> reporter: in this unusual case of dueling 911 calls and conflicting murder accounts, the prosecutor was confident that blood evidence would sink the son's story and fully support the husband's. >> who was your best witness? >> i think probably anna cox was, really. >> reporter: anna cox, a blood-stain expert, testified that kevin's blood was not only on his mother but also on her bed cover. >> if he says he wasn't in the room, does your scientific finding deny that premise? >> yes. >> there's no question in your mind. science tells you he was in that room. >> yes. you had to be right next to the comforter. >> reporter: to the prosecutor, it was a home run, confirming bill kyne's story -- that he opened the door and saw kevin straddling the bed on top of diane. and, loughery argued, kevin's bloo