tennis shoe. >> and i noticed in the flap of the edge of this shoe this tuft of what to me appeared to be wool. and that was it. we could find no other evidence. >> back at homicide, buffington showed the fibers to his superiors. >> the lieutenant made a big joke out of it and told the rest of the squad that if i went over to the lieutenant's house and cleaned out the lint trap in his dryer, we could probably clear out all the cases in the city of atlanta. >> still, buffington sent the fibers to the state crime laboratory. a young forensic scientist, larry peterson, took a look. why was that a fiber that was stuck in the crack of a shoe, why was that important? >> because it was somewhat loosely there. people normally don't have tufts of carpet fibers stuck loosely in their shoe.