A newlywed receives terrifying emails with threats of kidnapping and death; the emails appear to come from an ex-girlfriend, but hiding behind the threats is a cyber-secret.

At first it looked like a home invasion gone wrong at the house Ralph Candelario shared with his second wife, but when police learn the antique dealer's first wife had disappeared, they take a closer look.

Before time runs out, detectives race to find a Little Rock, Ark., realtor who went missing after showing a house.

Dark secrets come to light as officials investigate what happened to a wife and mother of three who was found dead in her bathtub.

A couple's romantic boat trip turns tragic when a young wife is lost at sea. Did she accidentally drown or was it something more sinister? The case was cold for years until a model with a checkered past goes undercover to find the truth.

She was a beaming bride. It was a haunting death. Sarah and Ryan were newlyweds when she drowned in the bathtub. Did she die of natural causes or was it deliberate? It took three trials to find the truth.

It all began when a bestselling author found his wife at the base of the stairs. Was this a fall or was it a crime? The story made headlines and we've been covering it for more than a decade. Here, Michael Peterson answers our questions.

A woman is murdered in a home invasion. Then, her best friend and neighbor is shot the following night. Investigators unearth disturbing secrets that suggest the cases may be linked.

When Cathy Torrez never came home after work, her family feared the worst. An intensive search ended after her car was found, with her body in the trunk. Who would commit such a savage crime? It take years to get to the truth.

A talented, young art student was murdered. The killer left no fingerprints and no DNA. Police zeroed in on three fellow students and, soon, the dark portrait of a killer began to emerge.

It's a gripping case that defies easy answers and Dateline has been following it for more than a decade. At the center, Steven Avery. He and his nephew were convicted of killing Teresa Halbach. Two sides. One truth. Who will you believe?

Nicole Pietz was a well-liked fitness executive married to the man of her dreams. Then one night, she didn't show up for dinner with her husband and friends. Had Nici's troubled past caught up with her or did someone want to harm her?

It was a marriage of opposites and yet somehow Debbie Kelly and Lars Itzo made it work. Then, Debbie was shot dead in the dark of night. Was her death a case of mistaken identity or the bloody end to a marriage gone bad?

When a young woman is found brutally murdered, investigators start to lose hope when they believe that the case is unsolvable, but the victim's mother is determined to get justice and figure out what happened to her daughter.

A young man from small town Indiana heads to Japan where he falls for a beautiful woman from a land nearly as far away. Then, one of the biggest natural disasters in history hits. With whole towns being wiped out, would they survive?

It was a crime not even police could believe: A toddler was shot in the head and left for dead. Despite the odds, she stunned everyone with her will to survive while a detective vowed to crack this case, no matter how long it took.

When Debbie Hawk vanished, her friends and family were left searching for answers. Investigators discovered that before she went missing, Debbie planned to reveal secrets. Police wondered if silencing her was a motive for murder.

A dedicated Air Force Captain who had been deployed overseas for long stretches found himself caught in the crossfire of a love triangle at home. Investigators discovered a tale of obsession and passion. Who pulled the trigger?

When Bonnie Craig was found dead, police collected DNA but it didn't match anyone in the system. Then, twelve years later, there was a hit but the man was thousands of miles away. Turns out, prosecutors would need more than DNA to convict a killer.

After a house fire in suburban New Jersey, investigators discover a twisted love triangle filled with jealously, love and murder.

She was a divorced mother excited about her next chapter in life. Then, five gunshots shattered her plans. Proving who murdered Joan Lockwood was a daunting task for police. An ominous killer was still out there and her family was living in fear.

This is a story about faith, temptation and secrets. A churchgoing mom was shot at point-blank range in her garage. Saving her would take a miracle and investigators wanted to know if this crime was random or if someone wanted her dead.

When Ricky Cowles and his girlfriend moved in together, her best friends moved in too; at first, it was like a big sleep over, then Rickie was found shot dead; his killer would let a secret slip, but turns out, he was keeping more than one.

Bob McClancy was a beloved detective. When his death was ruled a suicide, loved ones were suspicious. United by grief, his widow and good friend found themselves falling in love. Then Bob’s son started asking questions and uncovered a secret.

When a handsome veterinarian is found dead in a small Montana town, it launches a mystery that remains unsolved for years. After nearly two decades, investigators think they can solve it, but know convincing a jury will be no easy task.