. >> reporter: prosecutor john lewin would have to sell what was, perhaps, the most completely circumstantial case of his career. he enlisted co-cousel ethan miliuse this, cold cases, you never have one witness. you have a whole bunch of pieces. and on the surface, they don't appear to be connected. it's our job to connect them all together, to put it together to give you the final piece. >> so, no smoking gun, but then there really aren't any. >> the whole thing is a smoking gun. >> reporter: lewin fired the opening shot. >> the evidence will show, ladies and gentlemen, beyond any reasonable doubt that this man, douglas bradford, on august 30, 1979, in the middle of the night crept in there with that handmade garrote, got her while she was sleeping and brutally murdered her. >> reporter: then, more than 20 witnesses paraded by, each to recount a memory or offer an opinion, one tiny piece of the whole. >> the people call detective gary hilton, your honor. >> reporter: gary hilton was 72 now, still tormented by his inability to close the case. so, in a way, he was trying to clear his conscience here. >> i saw lynne knight's body. i never saw anybo