case file and discovered some important pieces of information. first, the witness who testified clarence elkins threatened judy johnson's life during a telephone call also claimed judy called 911 to report the threat to police. but there was no evidence judy johnson ever called 911. >> the 911 call should have been logged. it was obvious no such phone call had been made. >> and they also discovered that the coroner took vaginal swabs from judy johnson during the autopsy. on those swabs, lab tests found a substance known as acid phosphatase, an enzyme found in the male prostate gland. but those swabs were never tested for dna. >> to be fair, technology in forensic science is constantly improving. >> six years after the murder,