laci peterson. she was 27 years old. and on the night before christmas she was gone. >> laci, if you are out there and can hear and see us, we love you. and we are searching. we are looking. >> it hit something, something in the air. that name. that smile. that mystery. impossible to put down. >> whoever has her, please, please, please let her go and bring her back to us. >> we love her so much and want her back. please. >> and then there was him, the husband. the inscrutable scott peterson. >> i really don't care what people think of me as long as it keeps laci's picture and tip line in the media. >> before our eyes he would morph from a faithful husband who loved his wife to an object of suspicion and outrage. such a circus the whole thing seemed to be. but for all of the noise, all of the breathless coverage, the hours of tv and the acres of tabloids, there was and is a story never completely told. a story the prosecutors told "dateline" first. >> what do you think of scott peterson? >> he is a very unusual person. he