man: you're sure it's here? keith morrison: (voiceover) but as the searchers scoured the immediate area, they understood it couldn't be her. the bits of clothing weren't right and the bone was bleached by the sun. must have been there a long time. and when they looked closely-- that's a six foot something. it's not a 5 foot 5' female. keith morrison: (voiceover) appalling, some other poor soul wound up here, but relief too it wasn't michelle. so the search and the mystery wore on for days and then for weeks. and by the middle of august, it all looked to be losing steam. on a typical san francisco summer afternoon as the fog rolled in, christine and michael brought us up to date on their efforts to find michelle. how long has it been now? it's been over two months. it's been about 72 days.