DATELINE Preview: December 14 on NBC

After her mysterious abduction, Elizabeth Smart's triumphant return to her family left many wondering what really happened during the nine months she was held captive. Natalie Morales reports on the largely unknown details behind the kidnapping, recounting Smart's chilling story that helped lead a jury to convict her abductor on all charges.
 
Four years after an American business man is murdered in Thailand, investigators are faced with more questions than answers in a case involving an alleged hit man and an ex-fiancée. Though the search for justice continues, friends, family and the FBI believe someone could be getting away with the perfect crime. Chris Hansen reports.