Dateline: Secrets Uncovered

An old case is blown wide open by a confession years after a man is convicted of murdering Heidi Allen, last seen working at a store to earn cash for college.

Corey Parker's murder jolts a sleepy seaside community with the chilling realization that a killer is walking among them.

Pages from the diary of John Hinckley Jr., who was arrested in 1981 for trying to assassinate President Ronald Reagan, are revealed.

She yearned to make it in Hollywood. Instead, Brittany Tavar made headlines when she vanished. Investigators had plenty of leads - a handsome boarder, the friend turned enemy, or they wondered if the free spirit could have left on her own.

Realtor Lindsay Buziak thought she'd landed dream clients when a mystery couple said they wanted to buy a million-dollar home. What seemed like a golden opportunity turned deadly when Lindsay was murdered in the ritzy home.

They were a couple who seemed made for each other. Seemona Sumasar thought she had met Mr. Right, but her instincts proved wrong. Nothing was as it seemed.

In the California mountains, a young father calls 911 to report that he had been in a shoot-out with a car full of strangers. With one man dead and two others injured, authorities wonder if this was self-defense or something else.

It was a mystery from day one: A young father’s life cut short. Matt Podolak's death was puzzling. The word poison kept coming up. Matt’s brother embarks on a long quest for the truth.

Fences make good neighbours, but this one triggered a deadly fight. Only two men were there and the man who shot first told investigators his story. However, the crime scene was telling another story.

Two Tulsa, Okla., brothers fight for more than 20 years to prove their innocence after they are convicted for separate murders.

Lester Holt spends two nights locked up and embedded inside the largest maximum-security prison in America.

Before the Menendez brothers, the Bobbitts or even O.J., Pamela Smart was television's first true-crime fascination; Smart's husband was found murdered and when police began to investigate, they discovered that she was keeping a big secret.

Rod Covlin calls 911 after his young daughter finds his estranged wife unconscious in the bathtub; soon after her mysterious death, family members would come to suspect what happened was no accident.

When college student Mackenzie Lueck vanishes from a park in Salt Lake City, her friends are dedicated to finding answers; the search makes national headlines, and the investigation reveals a secret that stuns even her closest friends.

Police are perplexed when they find the body of a young woman but are unable identify her; with the help of amateur investigators and new DNA technology, a dogged investigator finds her killer and her identity.

Two tenacious sisters are determined to fulfill a promise to investigate the mystery surrounding their mother's death

When a model and up-and-coming YouTube celebrity is found dead, police question her husband to see if he can provide any answers.

The behind-the-scenes story of Rebecca Musser vs. Warren Jeffs, one of the FBI's most notorious fugitives; Rebecca opens up about life in the Fundamentalist Church of Jesus Christ of Latter-Day Saints, and why she decided to leave.

Gianni Versace's longtime partner, Antonio D'Amico, speaks about the murder of the fashion icon; Versace's murder came amid a monthslong manhunt for Andrew Cunanan, who was accused of committing four other murders throughout the U.S. in 1997.

Linda Watson was a single mom raising a beautiful daughter when she disappeared. Then, suddenly, Linda's mom was gone too, along with another friend. Police were convinced the three cases were connected, but unraveling the mystery took years.

The murder of socialite Nancy Phister sent shockwaves through Aspen; she was an A-lister in a city known for its opulent ski resorts and famous residents. Nancy had a long list of friends, but she also had foes.

Friends think something isn't right after the mysterious disappearance of a Colorado rancher and spend years fighting for answers.

The con artist known as Clark Rockefeller, a high society hustler with a talent for spinning lies, is suspected of murder; to unravel the mystery, cold-case detectives start to retrace his steps through a decades-old trail of deceit.

Two years after the disappearance of his wife, Josh Powell kills his two sons and himself. Watch Josh's last in-depth TV interview. Plus, a 911 dispatcher discusses the emergency call placed by a social worker.

She was a small-town girl from rural Wisconsin; he was a Chicago superstar, a hometown hero with the legendary Bears; together, they were expecting their first child, but no one was expecting their tale to end in the deadly way that it did.

A young woman is abducted in Ecuador and, as her family and investigators raced to save her, she plots to save herself; her daring plan involves a little something hidden at the bottom of her bag, but time is running out.

A small-town girl moved to Las Vegas where she found a new career and new love. Soon after, however, she vanished and within days police would find her body. Finding who killed her would be a tougher mystery to crack.

It is common for long-haul truck driver Lloyd Ford to be gone for stretches, and when he disappears, it doesn't raise many flags; at least two people know where he is, and they guard the secret for 27 years, but the truth is about to be revealed.

Brooke Wilberger was 19 when she was kidnapped; her family begged for her return, but months passed before police got their first break, a similar attack more than 1,000 miles away.

The murder of a young businessman in the Old San Juan district of Puerto Rico marks the start of a 15-year-long hunt to find the killer.

When hikers find a 21-year-old UCLA student's body in a Los Angeles-area train tunnel, detectives wonder if his interest in an alternative religion is connected to his murder.

Details expose how the Gucci family was undone by jealousy, backstabbing and, ultimately, an act of murder. Insiders close to the fashion empire speak out about the murder of a prominent family member.