after one month of analysis and retesting, norm tiller found what he was looking for. print on the pillowcase was a left thumbprint. it matched the outside of robert knight's left thumb. >> i spent additional time doing comparison work and just analyzing the print from every angle, so to speak, before we actually effected the identification. and even then, i had another examiner go behind me and take a look at everything that i had done to make sure there were no errors made in the process. >> but there was one more hurdle. the image enhancement technology was so new it had never been accepted as evidence in court. >> i was concerned at that point in time that the evidence may not be accepted within the scientific community as good science. >> a hearing was held to determine whether forensic evidence from this new fingerprinting technology should be admitted. the defense argued that it was hocus-pocus technology, which manipulated and changed the image of the fingerprint. pam ringer was the expert who testified for the prosecution, explaining that the human eye can dis