When high school student Megan Nichols vanishes from her Illinois home, her mother finds a note saying that she ran away; a grisly discovery made three years later changes the course of the investigation.

When the body of an Ohio woman is found in a wooded area near her home months after she went missing, investigators must determine if her death was a suicide or homicide.

The investigation into the poisoning death of Wisconsin mother-of-two Julie Jensen takes a surprising turn when detectives learn that Julie wrote a letter just days before her death pointing to a possible suspect.

A small Texas town is shattered when beloved teacher Manuela Allen vanishes from her home in the middle of the night. When a gruesome discovery is made a short time later at a local lake, investigators are left with more questions than answers.

When a young pregnant mother goes missing in Virginia, her family embarks on a frantic search, but the case eventually goes cold; years later, investigators speak with a woman who tells a harrowing story and may hold the key to solving the case.

After an apparent home invasion in Minnesota leaves Heidi Firkus dead and her husband Nick hospitalized, detectives learn the young couple was facing financial troubles.

A small Ohio town is left in shock after a local coal miner is found fatally shot in the basement of his home. As investigators dig into his personal life, a secret affair reveals a surprising suspect.

The murders of two young women near a Phoenix canal remain unsolved for over 20 years until a team of cold case detectives take on the case and investigate a man known as the Zombie Hunter.

After a nurse and mother-of-three is murdered inside her Illinois home, investigators uncover security camera footage that could be key to solving the case.

The investigation into the mysterious disappearance of a Canadian man sparks an international manhunt for an elusive killer with multiple false identities.

After police discover the burned body of a missing Miami man at the edge of the Florida Everglades, the wife of a local supermarket mogul comes forward to reveal a shocking secret and possible lead.

An investigation into the murders of several women found dead along Gilgo Beach in Long Island, N.Y.

Las Vegas detectives investigate the fatal shooting of a U.S. Air Force Airman.

Lead detectives break their silence on the investigation into once-prominent South Carolina attorney Alex Murdaugh.

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.

When 17-year-old Alissa Turney is reported missing in Phoenix, it takes years before detectives treat her case as a homicide; a new investigation unearths dark family secrets.

When 16-year-old Britney Ujlaky disappears, a small town in Nevada bands together to track down a potential suspect - an unknown cowboy; Soon, their focus turns to someone much closer to Britney.

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.

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

While responding to a house fire in New Jersey, firefighters discover the burned remains of homeowner Rob Cantor in the basement, leading investigators to question what really happened: new interviews and legal developments about the latest twists and turns in the case.

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

When deadly gunfire erupts in an Austin, Texas, home in the middle of the night, detectives wonder if the homeowners' jewelry business is a possible motive; an investigation uncovers a suspect that no one saw coming.

New details on the latest twist in the murder-for-hire plot involving a prominent Florida family that left law professor Dan Markel dead and a grandmother arrested.

Navy petty officer and devoted mother Sherri Malarik is found shot to death in her minivan after she disappeared. The case remains cold until new revelations and old memories resurface, dividing the Florida family.

Law enforcement investigates possible motives after a package explodes at a Southern California day spa, leaving a beloved esthetician dead.

A mystery looms over a small New York town when a woman is murdered and a stunning secret is exposed; more than a decade later, new developments lead to an unexpected conclusion.

A series of mysterious events haunt 16-year-old Cassie Jo Stoddart while housesitting, and days later, she's found stabbed to death; police retrace her last day and uncover a stockpile of evidence pointing right to her killers.

After more than 20 years, the real killer of Idaho teen Angie Dodge is caught; a chilling twist in the story of Chris Tapp who had been wrongfully convicted in the case. Keith Morrison reports.

New interviews and never-before-seen evidence about the murder of Jennifer Dulos, including video and photos from residential security systems and urban police cameras that detail the timeline of the crime.

When a firefighter is murdered, the investigation unravels a web of secrets, a love triangle and stunning surveillance footage. Dennis Murphy reports.

After a 25-year-old mother is gunned down in broad daylight by a murderer wearing a disguise, detectives confront a most unlikely suspect. Dennis Murphy reports.

Twenty-seven-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.

New details and interviews about the murder of a professional cyclist.

When Joy Hibbs is found dead in a fire, an autopsy shows she was murdered beforehand. The case went cold for years, until decades later, a shocking secret is revealed. Blayne Alexander reports.

The separate murders of two women in Toronto ignite an investigation that spans four decades, taking detectives from the big city to a remote, northern town.

A woman goes missing and investigators uncover her husband's chilling history including dark secrets about another missing wife.

In Southern California, initial signs point to an accidental fall down a staircase as the cause of Susann Sills's death in 2016. Does the evidence disprove her husband's story?

When the wife of a popular DJ is found murdered, detectives try to unravel what led to her killing.

A group of women help bring down a smooth-talking serial predator turned killer who lured young women with promises of fame and fortune.

Two women are murdered in the same Arlington, Texas apartment complex, and police are stumped. Years later, evidence from two subsequent rapes provides a breakthrough. Andrea Canning reports.

When a nurse is gunned down in her home, detectives initially believe they have a clear suspect, but new information leads them down a completely different path. Josh Mankiewicz reports.

In May 2017, 22-year-old 8-months-pregnant single mom Akia Egglestion vanishes before her own baby shower and her worried family raises the alarm; Baltimore, MD detectives unravel a chilling mystery.

A family is rocked when a fatal accident reveals itself to be something much more disturbing.