Disappeared - Season 4

The case of 19-year-old student Rachel Cooke, who vanished after leaving her parents' Texas home for her regular six-mile morning run in January 2002.

The disappearance of Steven Koecher from Utah. After the case yielded few leads, investigators looked into a possible link with another missing person case and a long road trip the clean-cut Mormon took some time before he vanished. 

The story of 20-year-old Virginia Tech student Morgan Harrington, who disappeared at a Metallica concert in 2009. Three months later, the heavy metal fan's battered body was found 10 miles away, but police were unable to identify any suspects for her murder. 

The case of University of Massachusetts student Charles Allen Jr, who was due to meet a friend before a party but never showed up. The same day in October 2007, the 22-year-old had told his sister that he feared people were after him. 

On February 13, 2001, Pat Viola calls her mother to have a chat during which nothing seems odd, but Pat is never heard from or seen again.

The case of former psychology student Alicia Amanda Stokes who disappeared from her Oakland apartment in 2007, following an argument with her brother. Her car was later found parked near a steep ravine with all her personal effects inside, but its driver was nowhere to be seen. 

The case of 23-year-old Leah Peebles, who vanished in New Mexico in May 2006. When her father tried to find her, he discovered she had been using drugs and working as a prostitute. 

The case of mother-of-four Amber Gerweck who went missing in April 2011. Her car was found in Georgia, 600 miles from her home, and when Amber eventually reappeared she claimed to have no recollection of events over the previous three weeks. 

The case of 15-year-old Colleen Orsborn, who went missing during Daytona Beach's spring break season in 1984. Though clues exist to suggest she was a murder victim, a killer was never identified and her body has yet to be found.

The case of Florida businessman Mike Williams who went missing on a duck-hunting trip to Lake Seminole in March 2000. His truck and shotgun were recovered, but his body was not, leaving open the possibilities he had been taken by alligators or was the victim of foul play. 

The case of Vermont teenager Brianna Maitland, who vanished after leaving her family's farm after dropping out of high school, intent on getting her life back on track. Four days after the 17-year-old was last seen by friends in March 2004, her slightly damaged car was recovered from outside an abandoned farmhouse. 

The case of Lily Aramburo, who vanished in June 2007, abandoning her nine-month-old son Palden and leaving her purse and phone at home. She was last seen leaving her fiance's condo wearing only a nightgown and carrying two bungee cords. 

The case of 27-year-old wife and mother Tina McQuaig, who disappeared from her home town of Jacksonville, Florida, in March 2000 after leaving her job at a pharmacy. Almost three years later, DNA evidence confirmed that remains discovered at a nearby wooded area were hers and it was also determined she met a violent death. However, the investigation failed to progress further. 

The case of 22-year-old Jamie Fraley, who vanished from her North Carolina apartment in April 2008. Her keys and purse were found locked inside her apartment and there were no signs of foul play. Officers considered whether her boyfriend's father could be involved, after it emerged that he harboured a dark obsession with her.