clippings from a purple bedspread and from a yellow blanket. >> your blanket was located under wayne williams' bed. >> on the floor, a green carpet. this is a blow-up of those carpet fibers. >> they're the only company to produce a fiber like this. >> but larry peterson was still in the dark. >> i had no idea there was a bridge incident. >> he had been called to the fbi office to help search this station wagon. but not told why. then he spotted fbi techs returning from their search and so he went out to the home to snip fibers for himself. >> saw all the green carpet. >> did you feel, this is it? >> you know, i really didn't. >> because it was a middle class home. a young man living with his parents. but peterson thought -- >> i'm going to run this back to the lab and just look. i started with the green carpet.