In my country there was a TV program about missing people called "¿Quién sabe dónde?", something similar to "Who knows where?". It had high audience and solved a lot misteries about people who disappeared without a trace.
The audience had the most important role because of their calls about sightings. Those calls were the key to find out what happenend with the missing people.
I remember one of the case histories about a middle-aged man who had lost his memory and didn't remember his name nor his history. The most shaking moment was when his mother spoke with him and he began to recover his memory step by step.
It was one of the programs that more helped people in the history of TV.