Stephanie Crane, aged 9, walks home from the local bowling alley-but never arrives. Early leads go nowhere. For years authorities don't find her or make an arrest. Now, they hope that advances in evidence testing may finally solve the mystery.

When Sage Smith, a transgender teen in Charlottesville, Virginia goes missing, police identify a suspect. But the investigation turns up evidence that forces detectives to look closer into Sage's inner circle to see if there are answers.

Nineteen-year-old Tyarra Williams vanishes from the parking lot of her Greensboro, N.C., apartment complex. When tips suggest that Tyarra may have fallen prey to human trafficking, her grandfather embarks on a cross country search for answers.

Mother of three, Holly Cantrell, is seen on security video exiting the Oklahoma hospital where she works but never returns home. Police learn Holly was keeping secrets, and her loved ones wonder if those had anything to do with her disappearance.

While on a Caribbean cruise, 23-year-old Amy Bradley vanishes from her family's cabin and is never seen again. Over a decades-long struggle, her family embarks on countless grueling searches, stopping at nothing, they say, to find their beloved Amy.

When Michael VanZandt, a veteran and father of three, disappears one night in Hermosa Beach, Ca., police suspect a group of strangers may be involved. But his loved ones are haunted by suspicions about his thrill seeking when considering his fate.

Ali Lowitzer vanishes after getting off the school bus. The investigation stalls for two years until a tip comes in claiming Ali could have been trafficked. A SWAT team busts a prostitution house, but will it bring 16-year-old Ali home?

Thirteen-year-old Tabitha Tuders vanishes while walking to her bus stop in Nashville, Tenn.; police think she's a runaway, but there are disturbing circumstances surrounding her disappearance, leaving her family desperate to find the truth.

College sophomore Martin Roberts is a popular fraternity brother, suddenly he goes missing. The only clue he leaves: a cryptic note. Baffling secrets emerge. But two years later, his family remains desperate to know what has happened to him.

When 70-year-old retired firefighter Michael Chambers goes missing, a bloody crime scene in his garage quickly indicates foul play. But authorities begin to believe that the crime scene may have been staged and that Michael may have left on his own.