Cold Case Files — Episode 20: The Flaming Gorge Falls/Caught in the Mail

You are watching the episode The Flaming Gorge Falls/Caught in the Mail A man suspected of the cold case murder of his wife and son hatches a new plot to kill his mother and father; and detectives solve the 20-year-old murder of a teenager by tricking her killer into licking an envelope, then extracting DNA from the saliva.