The police. Then there was this secret boyfriend who wasnt telling all he knew. It was suspicious to police he wasnt upfront from the beginning about that. There was a third man. The former colleague with a crush. Cliff shared with friends he had found the love of his life. So you have three potential suspects. Yeah. Its a tangle. Could investigators unravel it. Were asking what does this mean. Would her family ever find justice . 17 years of builtup emotion, you know. Im lester holt and this is dateline. Heres andrea cannon. Its a celebration no mother would ever want to miss. A childs 5th birthday. But suddenly she was gone. Out of his life. Theres nothing that anybody could really do to fix that or, you know, repair that missing part. His mother, Sandy Johnson, was outgoing, energetic and an awesome mom. Those kids were everything to her. So why wasnt she there to sing happy birthday to her son . All they knew was she disappeared into thin air. She should have seen you get married.