. >> reporter: donald williams is a retired oakland cop who now investigates cold cases for the department. none colder than the one he's looking at now. none more disturbing either. >> gruesome? >> this is about one of the most gruesome ones i've seen. >> reporter: our case begins to july 28th, 1980. a torso is found near the corner of helen and peralta streets. there is no head, no arms, no legs. just disembowelled and burned remains. the original police bulletin on the crime contains this chilling assessment. the dismemberment is so cleanly performed it indicates the suspect may have had some type of anatomical background. >> for someone to do something to a human being this way is just incredible. >> reporter: but police have no idea, no clues as to who their victim is. so the investigation stalls almost immediately. but just one year later and ten miles away, a driver looking for a lost hubcap finds a skull just off grizzly peak boulevard in the hills above oakland. those remains, however, are handed over to the authorities in contra costa county, not alameda. it's a move that inadver