fact that he had no witnesses. >> you know, not just the blood spatter, but the fingerprints. and then, you know, the dna off the sweater. all of those things that kind of pointed back toward george hansen. up next, a vibrant real estate professional is brutally murdered. >> this involved the entire range of violence. >> even hardened professionals are troubled by what they see. >> for there to be that much blood left at a scene, that's what we consider overkill. >> police find a possible witness and try hypnosis to get every detail. >> how many times do you see a composite sketch and you're like, okay, this looks just about like every human being on the face of the planet? >> it was a real whodunit. and i hate whodunits. >> the killer leaves behind a clue, but would it it be enough? >> people will kill for the most trivial of reasons. ♪