apartment. at 12:30 that morning. and then made a phone call to jenna a few minutes later to tell her good night. >> phone records showed that he had placed a call at 12:47 a.m. >> we know that she was discovered about 11:30 the next morning. so we've got less than a 12-hour window when jenna was killed. >> during the autopsy, the medical examiner found no evidence that jenna had been sexually assaulted. but he couldn't rule it out either. >> it has been my experience in some 30 years of performing autopsy examinations that the lack of genital injuries does not rule out a sexual assault. >> but he did find small, broken blood vessels in the whites of jenna's eyes, known as petechial hemorrhages. >> they're in that constellation of findings that we refer to as stigmata of asphyxiation. tells me i need to look for a cause of asphyxiation.