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

Their evenings begin as fun celebrations with friends but they end in murder. With disturbing evidence, terrifying theories, and demands for justice, can the mystery of how two young partygoers are murdered be solved?

A young Hollywood celebrity is out celebrating her birthday and another young woman enjoys a late drink with friends, just a few hours later, they both end up dead and investigators try to solve the mystery. 

Two young brides-to-be are just beginning to plan their weddings when their dreams are tragically cut short. Can desperate calls made to 911 reveal the truth about their shocking deaths?

When two young women vanish without a trace, investigators are haunted by the things they leave behind - a car with the keys still in the ignition, a pair of shoes, and a coat. They disappear with no warning. Where have they gone?

They are head over heels in love with their whole lives ahead still ahead of them, but then they die suddenly under suspicious circumstances. Could the strange text messages that come from their own phones hold the clues that investigators need?

Two young women who dream of big success as television anchors are just embarking on their careers when their plans come to a violent end. They are murdered in their own apartments and there are no signs of forced entry. Did they know their killers?

A respected police officer heads home after a late shift, and a young man who has just moved into his own place relaxes after watching football. How do these routine evenings turn deadly? Were their killings cold-blooded assassinations?

The murders of a teenage boy who never returns home from school and a teenage girl who is ambushed as she sits in a car with friends devastate their communities. It is every parent's worst nightmare - who would kill two innocent teenagers?

No description available

They are the victims of shootings that seem senseless. Who would want them dead? Did these two young people get tangled up with the wrong crowds? And will anyone be held accountable for their murders?

After struggles in their youth, they are setting out on new paths with new hope but then the unthinkable happens. Their horrific murders are chilling. Who would kill them in such a violent way? Did they have any idea how much danger they were in?

She is an innocent bride-to-be; he's a six-year-old schoolboy. Both are on the road, away from home, when they disappear. When her car and body are found, will the clues lead to her murderer? And will his family ever solve the mystery of his vanishing?

Two 20-year-olds suffer personal tragedies then have their own lives abruptly snuffed out. He's shot while hanging out with friends; she disappears, only to turn up dead in a staged suicide. Will their families be able to prove what really happened?

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?

One young woman is found with a shotgun wound to her head shortly after moving in with her new boyfriend. Then, a couple planning their wedding are gunned down in their own backyard. Will secrets from the past explain these unimaginable deaths?

The body of a young musician turns up in an alley. Police learn she's been spending time with an older man. Did he play a part in her murder? And when a construction worker disappears on the job, his coworkers' accounts don't add up. What are they hiding?

A mother of three is gunned down in a church basement where she's set to teach a fitness class. Police find surveillance video showing a figure in full police body armor stalking the floor in the lead-up to the slaughter. Who is this craven killer?

When two women die suddenly under mysterious circumstances, authorities initially suspect suicide. But both of their families believe it was murder, and are trying to figure out who is responsible.

A mother of two and a young woman planning a career in science both die under mysterious circumstances, and two families embark on quests for justice.

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