An anonymous letter leads authorities investigating the poisoning death of a chiropractor to an unlikely suspect.

A comprehensive look at the 1989 murders of José and Kitty Menendez by their sons, Lyle and Erik; featuring interviews with key players in the case, including Lyle Menendez.

An investigation of a woman found murdered in Fort Worth, Texas.

Author Rachel Jeffs talks about what it was like to grow up as the daughter of the self-proclaimed prophet of the Fundamentalist Church of Jesus Christ of Latter-Day Saints, Warren Jeffs.

A young father's murder at work leads investigators to deep secrets about sex, friendship, religion and family.

A community comes together to search for a young woman who goes missing from a Halloween party.

As a murder victim's sisters dedicate themselves to finding the killer, an unexpected source turns the case upside down.

When a model and up-and-coming YouTube celebrity turns up dead, police question her husband in the hope he can shed some light on the situation.

When a mother of four dies unexpectedly on Valentine's Day, her death is attributed to natural causes, but a detective suspects that someone murdered the woman.

A love triangle leads to years of stalking, property destruction, threats, and murder.

When a father goes missing and his body is found in a field several miles away, the investigation reveals multiple suspects -- including members of his own family.

When film executive Gavin Smith vanishes, Los Angeles detectives search for clues amid reported sightings and suspicious circumstances.

A luxury car salesman is asked by a beautiful former client to plan a murder.

A former hockey player discovers his wife murdered in their own home. His young daughter says she saw a robber, but the killer's true identity turns out to be far more complicated. Andrea Canning reports.

Kate Snow speaks with two families about their unforgettable stories of surviving the 2013 Westgate Mall terrorist attack in Kenya.

When college student Mickey Shunick vanishes, her sister becomes the driving force in a multinational search effort.

When a beloved firefighter is murdered just outside Sarasota, Fla., investigators discover a twisted tale of secrets, lies and infidelity. Andrea Canning reports.

An in-depth interview with Charles Manson's former parole officer; rarely seen video of Manson; interviews with victims' family members, and others close to the case.

An unexpected revelation may change the fate of the man convicted in the case of a young woman found dead in the Kentucky warehouse where she worked.

The battle between a wife and a mistress for the heart of one man leads to a deadly car chase. Andrea Canning reports.

When a fire is set to cover a murderer's tracks in Bergen County, N.J., for the third time in a year, authorities suspect a serial killer may be on the loose.

A woman continues searching for answers after the investigation into her daughter's murder goes cold.

Police investigate whether the shooting of a young woman in Utah was an accident or something more sinister.

When a man in San Antonio shoots his wife in the dark of the early morning, he says he mistook her for an intruder.

First responders are met with horror when they discover a young woman's body in the basement of her home in western Massachusetts.

The murder of a woman in Saco, Maine, leads police to a complex investigation that spans three states.

When a mother of three mysteriously disappears, the only clue is her abandoned vehicle on a lonely Montana highway.

A woman comes forward with the truth about the deaths of three other women, solving a 17-year-old mystery; interviews with two people at the center of the case.

When Cara Ryan shoots her ex-husband and accuses him of threatening to kill her, police question her motive.

Princess Diana's troubled marriage, life in the monarchy, love affairs and tragic death; interviews with former bodyguard Ken Warfe, Paris police chief Martine Monteil, forensic scientist Patrick Touron, former French diplomat Sami Nair, and others.

A look back at the 1997 murder of fashion designer Gianni Versace, including interviews with his long-time partner Antonio D'Amico, model Beverly Johnson, fashion journalist Hal Rubenstein, author Maureen Orth and more.

A look at the 2004 murder of pregnant California woman Laci Peterson, including previously unseen interrogation footage of her husband, Scott, who was convicted of the crime.

A detective comes face to face with a serial killer when she promises to get justice for the mother of a victim whose body turns up at an Anaheim trash facility.

After a young mom is found dead on the side of a country road, 40 miles from her Knoxville home, investigators scramble to figure out how she ended up there.

Michael Peterson, who was granted a new trial after the 2003 conviction in the murder of his wife was overturned, discusses the case and his decision to enter an Alford plea.

The investigation into the disappearance of a mother of three in Colorado reveals she was living a double life.

When a 23-year-old woman goes missing from a shopping mall in Plano, Texas, her family searches for her, while the police seek out who is responsible for her disappearance.

When a former hockey player discovers his wife murdered in their home, his daughter says she saw a burglar.

Two double homicides committed five years apart lead police to suspect a serial killer is responsible.

A tight-knit Long Island family go to extraordinary lengths to find their missing sister.

Police investigate whether the murder of a South Florida attorney is connected to a web of fraud, betrayal and more than $1 billion in missing money.

Michelle Hadley is exonerated after spending three months in jail for attempted forcible rape of her ex-fiance's wife.

Co-lead investigator in the Steven Avery case Tom Fassbender discusses the case and allegations investigators coerced Avery's nephew, Brendan Dassey, into making a false confession.

When two women are murdered five years apart in different states, a private investigator looks for connections between the two cases.

Against all odds, a young woman is found alive after an attack on her and a friend near Corpus Christi, Texas.

Celebrating journalist Tom Brokaw's 50-year career; highlights, famous interviews, never-before-seen moments and new conversations with guests -- including Oprah Winfrey, Bill Gates, Tom Hanks, Jon Stewart, Lin-Manuel Miranda, Colin Powell and more.

A relative and a friend of Ross Harris -- who forgot his 22-month-old son in a hot car for hours -- speak out about the case.

The FBI gets involved when a Virginia man's wife and son are kidnapped while vacationing in the Philippines, with a terrorist group demanding millions in ransom.

A man convicted of murdering a woman in her upscale Austin, Texas, home tells his story for the first time.

President Barack Obama discusses how he feels he delivered on the promises he made at the start of his time in office and his hope for the nation going forward.