Eighteen-year-old Brookelyn Farthing disappears in 2013 after attending a party in Berea, Ky.; 24-year-old realtor Lindsay Buziak is found brutally killed after showing new clients a million-dollar home.

Thirteen-year-old Abby Williams and 14-year-old Libby German disappear while hiking on a popular trail; 13-year-old Dylan Redwine vanishes over Thanksgiving break while visiting his father in Vallecito, Colo.

Florida insurance agent Carla Stefaniak vanishes in Costa Rica; 19-year-old college student Pravin Varughese disappears after a party in 2014.

After a night out with friends, Jaleayah Davis, 20, is found dead; Kelsie Schelling, 21, drives two hours to show her boyfriend a sonogram of their baby, but never makes it home.

In Mobile, Ala., young mother Danniella Vian, 25, disappears into thin air; 19-year-old Holly Moore's suspicious death still raises questions four years after her body is found hanging in her closet

Officers discover a high school senior's strangled body in flames weeks before graduation.

A bride-to-be vanishes weeks before her wedding. Suspicion swirls around her fiancé and ex-boyfriend, before a shocking revelation about a coworker makes him the main person of interest. Then, the mysterious death of a young trans woman.

A college student sends his sister a mysterious text about leaving the country. Later, his body turns up in a lake, weighed down by a backpack full of rocks. A young woman vanishes after trying to make a call from a payphone.

A young woman acts erratically at a restaurant and police take her into custody. They release her in the middle of the night(—)and she disappears. A soldier at Fort Hood dies after falling off a balcony. Was it an accident, suicide or murder?

The families of two young mothers who die in suspicious circumstances search for answers. Racheyl Brinson's husband says she fell to her death while hunting, while Jessica Alva's boyfriend tells police that she hung herself.

A Georgia man suffers 17 stab wounds while on a hunting trip, and authorities rule his death a suicide, shocking his family. Another man disappears without warning -- the only clue is his burned-out car, found 14 hours from where anyone saw him last.

Oakley Carlson is missing and no one can find her, including her foster parents and her biological parents; a young mother leaves a bar with a man she doesn't know and ends up dead.

A truck driver finds an unconscious woman on a Missouri motorway, and police determine the suspect attacked her elsewhere and placed her on the road; an unknown killer bludgeons a mum and her daughters at home while her son and nephew cling to life.

The murder of billionaire couple Barry and Honey Sherman in their mansion stuns Toronto, since Barry is a pharmaceutical mogul with many enemies, but it is unclear who would kill his wife; a New York teen disappears after a mysterious road trip.

A 14-year-old disappears in Aruba while on a jet ski ride with an older man; a man kidnaps a young woman from the parking lot of her boyfriend's apartment building.

A rookie police officer is heard confronting someone with a gun and is shot in the back of the head, but the D.A. believes it's suicide. And when a Navy veteran is discovered with wounds all over his body, police oddly think he died of pneumonia.

A young woman's body is found 200 miles from home, and a retired police detective uses his podcast to crowd-source the search for her killer. And, when a young mother disappears, an old answering machine message could hold the key to finding her murderer.

Sisters seek justice for their siblings - but the truth might be deadly.

Someone snatches a baby boy from his crib, and a young mom goes missing.

Home becomes the most dangerous place on earth for two lovely young women.

A man and his dog burn to death. A chase ends in murder for a motorist.

A 14-year-old boy vanishes, but neighbors don't tell police what they know.

A young woman on a trip to her father's homeland goes missing, then turns up brutally murdered. Another young mother and her baby are shot as they drive along a highway.

The murder-suicide of a mother and son may be something entirely different.

Two young women are savagely murdered. One has gone fishing only to turn up beaten and drowned, and the other is a pregnant mother attacked while on the job delivering newspapers. Are strangers responsible, or are the culprits much closer to home?