Information found on social media leads investigators to a Wisconsin couple's killer.
When a man goes missing, his friends turn to social media to track his final hours. What they learn is horrific. "48 Hours" correspondent Erin Moriarty investigates.
When a woman vanishes and misses a hair appointment, her hairdresser becomes the driving force to find out -- did she leave her husband or is she dead? "48 Hours" correspondent Peter Van Sant investigates.
A star snake breeder is murdered. Turns out the human closest to him was more cold-blooded than any snake. "48 Hours" correspondent Peter Van Sant reports.
Inside the mind of murderer Mark Twitchell. Newly revealed letters from the man police say wanted to be like fictional serial killer Dexter. "48 Hours" contributor Troy Roberts reports.