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?

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.

No description available

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?

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.

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

A man's trip ends badly. A missing mom's search party sparks suspicion.

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?

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?

A girl vanishes on her way home, and an entrepreneur dies after a fight.

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.

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?

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?

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?

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?

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 beer entrepreneur is gunned down, and two friends die while on vacation.

One mom is missing and another spurs a manhunt for her daughter's 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 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.

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

A severed foot is an ominous clue in the case of a missing mother of five.

In an ironic twist, a woman vanishes while looking for her missing friend.

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.

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?