Kelsie Schelling disappears one night after leaving work, leading family and investigators on a four-year hunt to find the pregnant 21-year-old; cell phone records reveal what happened to Kelsie.

After trumpet player Scott Sessions fails to show up for a scheduled gig, his family learns his body was abandoned in the remote Colorado Rockies; as the investigation narrows in on two suspects, a second murder catches police by surprise.

Police bodycams capture officers rushing to Amy Allan's house after her husband called 911 to claim she'd taken her own life; investigators delve into forensic evidence and mobile data to solve the crime.

When a U.S. Air Force Airman is shot multiple times inside his garage, a trail of clues leads Las Vegas detectives to a secret love affair and a murderous plan.

A mother searches for answers in the unsolved murder of her 14-year-old daughter until new DNA technology changes everything.

Firefighters make a grisly discovery of the body of 39-year-old wife and mother Carmella Knight after responding to a house fire outside Toronto. An elaborate undercover sting reveals a devious murder-for-hire plot.

A woman is found executed on a rural road 25 miles from downtown Laredo.

When young mother and paramedic Annamarie Cochrane Rintala is found dead at the bottom of her basement stairs, it takes four trials and 13 years before justice is served.

When Idaho police retrace the final hours of 16-year-old Cassie Jo Stoddart in 2006, they uncover evidence including a homemade horror film that points to her killers. Keith Morrison reports.

After Tahereh Ghassemi disappears from the Louisiana home she shares with her adult son, detectives discover that she'd recently come into a great deal of money. The investigation reveals an astonishing plot with international implications.

A month after Mollie Tibbetts' disappearance in Iowa, investigators discover surveillance video that captured a blurred image of Mollie jogging while being followed by a mysterious black car.

A nurse is gunned down in her home and detectives believe they have a suspect. As they delve deeper into the investigation, new information leads them down a completely different path.

Private Investigator and former police officer Taylor Wright vanishes, but detectives think there is more to the story after her girlfriend receives strange text messages from Taylor's phone.

Detectives in Washington, D.C., discover a puzzling connection between two women who disappeared two decades apart. An investigation reveals a sinister secret hidden along one of the busiest stretches of interstate in the country.

27-year-old Egypt Covington is found murdered in her home. Investigators in Michigan quickly identify a person of interest, but years pass without an arrest.

A family begins a relentless pursuit of justice after the death of Nevada attorney Susan Winters is ruled a suicide; Susan's parents open up about the 7-year case and their efforts to push back against the criminal justice system.

After the cause of the death of Stacy Feldman in her Denver home is ruled as undetermined, friends and family join forces to piece together what happened. Insiders close to the case speak out about the seven-year battle for justice.

After Florida teacher Denise Hallowell is found murdered in her home, investigators examine her family's tumultuous past in their desperate search for a killer.

After New Jersey mother Michelle Lodzinski reports that her 5-year-old son has vanished from a carnival, detectives embark on a decades-long investigation until a family member identifies a key piece of evidence pointing to a potential suspect.