no >> emotionally unsatisfying not to have that answer. >> so it is, even if we've seen something or we think we have. and that's the question at the heart of a whole puzzle. is this woman right? >> i know what i saw, and i know the conclusion of my story. >> of course she does. of course she does. so why does this other women think this? >> she doesn't know for sure what she saw. >> a question, we say, on which all the rest will turn. why don't we begin here. calimesa, california, riverside county. historic missions. sprawling suburbs creeping out to the rim of mountains around the eastern flank of los angeles. here is where chris and cristi hall had come to live out their golden years, though they were far from old when it happened. just experienced, with life and each other. >> as far back as i can remember, it's always been