death or even a suicide. but then six weeks later, something that changed the entire focus of the investigation. emily's toxicology report came back. >> results came back clean. she wasn't under the influence of opiates at the time of her death. >> so it wasn't an overdose? >> wasn't an overdose. >> no trace of the opioid pain pills emily had been abusing. there was nothing in her system that would have killed her. there was no alcohol in her blood. so now investigators had to take a new look at the case, starting with the photos of the bruises on emily's body. remember, police saw a bump on her head, but during her initial exam, the medical examiner found more. >> she had areas of trauma to all four sides of her head. so the front of hehead, both left and right side of her head d the top of her head. >> possible those injuries could have occurred while alex was dragging his wife out of the tub? >> i don't think so. >> and there were bruises on emily's neck.