>> there was a problem. investigators couldn't see the print clearly. they sent it to the fbi in washington, d.c. fbi image analyst scanned the image and examined it digitally on a computer. he immediately saw the problem. the texture of the skin on the victim's leg obscured the fingerprint. >> there were two patterns we are dealing with. you are dealing with the pattern of the fingerprint which is a specific type of pattern and then we have this texture of the skin that is distinct from the fingerprint. >> with the aid of the computer, he to first identify the victim's skin pattern and then have the computer remove as much of that as possible. >> it's a trial and error technique. it's not unlike an archaeologist using a dental tool to scrape away fine pieces and leave the