Gianni Versace’s longtime partner Antonio D’Amico speaks about the murder of the fashion icon. Versace’s murder came amid a months-long manhunt for Andrew Cunanan, who was accused of committing four other murders throughout the US in 1997.

She was an A-lister in a town famous for glitzy ski resorts and celebrities; when socialite Nancy Phister was murdered, the news reverberated around Aspen; Nancy had a long list of friends, but she also had enemies.

In a suburb of Toronto, a family lives in fear as one relative after another is found dead over the years in the same house.

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.

Fences make good neighbors, 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.

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

Heidi Allen was working at a store to earn cash for college and was last seen there when she vanished. A man was convicted of murdering her, but years later someone else confessed to friends that he did it, blowing the old case wide open.

Linda Watson is a single mom raising a beautiful daughter when she disappears; then, suddenly, Linda's mom goes missing too, along with another friend; police are convinced the three cases are connected, but unraveling the mystery takes years.

Corey Parker had plenty of admirers, but maybe one of them liked her too much. Her murder jolted a sleepy seaside community with the chilling realization that a killer was walking among them.

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.

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

A small-town girl moves to Las Vegas, where she finds a new career and new love; soon after, however, she vanishes, and within days, police find her body; finding who killed her will be a tougher mystery to crack.

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.

Uncovered pages from John Hinckley Jr.’s diary are revealed. Hinckley began writing after he was arrested for trying to assassinate President Ronald Reagan.

Two Tulsa brothers fight for more than 20 years to prove their innocence, after they were wrongfully convicted for separate murders;

When college student MacKenzie Lueck vanished from a park in Salt Lake City, her friends were dedicated to finding answers. The search made national headlines and the investigation revealed a secret that stunned even her closest friends.

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.

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.

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.

A high-society hustler with a flair for spinning lies, the con man known as Clark Rockefeller is accused of murder; to solve the mystery, cold-case detectives begin to retrace his steps along a decades-old trail of deceit.

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.

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