A couple takes a scuba-diving trip to the British Virgin Islands; on their last dive, one of them surfaces but the other does not; police quickly suspect the drowning was no accident; now Dennis Murphy gives this unforgettable story a second look.

Andrea Canning looks back on the royal who has fascinated her since childhood, Princess Diana. She explores Diana's real story, including a look at her troubled marriage, turbulent life and the investigation into her death.

A series of reports chosen by "Dateline" correspondents that answers the question they most often get asked -- what their most memorable story is and why.

Newlywed Dalia Dippolito comes home from the gym to find out her husband has been killed; in a case Dennis Murphy will never forget, almost nothing is as it seems; he explores whether Dalia was a pawn in a hoax gone wrong or simply diabolical.

Debbie Kelly and Lars Itzo make their marriage of opposites work; when Debbie is killed, there is no question about who shot her, yet the explanation of why is one of the most confounding Andrea Canning has heard.

The heir to a legendary hotel is brutally murdered, and detectives learn he had no shortage of enemies; Dennis Murphy takes a fresh look at this extraordinary investigation, a hunt for a killer he calls the most ruthless he's ever seen.

A woman finds her father, a former FBI agent, murdered at his house; after digging into his past, police suspect the killer might be close to home; for Josh Mankiewicz, the toxic marriage at the heart of this case makes it unforgettable

After a young woman's body is discovered at a trash facility, a detective promises justice and comes face-to-face with a serial killer; Keith Morrison revisits the case.

An advocate for the missing Indigenous women looks into the disappearance of her niece and uncovers some issues in the law enforcement.

For more than 30 years, Ohio investigators have searched for answers in the murder of 10-year-old Amy Mihaljevic. The details of the case still haunt Josh Mankiewicz. Now he and investigators are enlisting your help to solve it.

Eduardo Valseca was kidnapped in a planned kidnapping. Keith Morrison reflects on the family he spent years trying to track down. The Valecas were not destroyed by what happened to them.

A novelist's wife is found dead at the bottom of the stairs. Investigators wonder if it was an accident or murder. Dennis Murphy interviewed main suspect Michael Peterson and now returns to the case with insight only he can share.

Nathan and Denise Leuthold built their family on faith, but suddenly one of them was dead and the other was under suspicion. It's a story that stays with Andrea Canning, both because of what happened and when it happened: Valentine's Day.

Keith Morrison revisits a story that has haunted him for years. When detectives find a missing woman's car abandoned on a bridge, their investigation uncovers a tangled plot involving money, friendship and a deadly betrayal.

Gary Hilton is a name Dennis Murphy will always remember. A hiker goes missing and authorities suspect Hilton is reenacting a slasher movie. Dennis reflects on the real-life murder spree that terrorized the American South.

After a 15-year-old girl disappears, investigators discover a creek where the local teenagers hang out. This hideaway may hold answers. Dennis Murphy looks back on the case that kept him guessing until its astonishing conclusion.

Years after a Montana man is found dead, his son searches for answers. Keith Morrison cannot forget that son who opened a box, and faced a terrifying family secret.

When a pastor loses a second wife in an accident, authorities become suspicious. Dennis Murphy returns to this unforgettable story of evil and betrayal, wondering how far this a man of God might have fallen. Dennis still can't believe the answer.

A man claims his wife died by suicide. A suspicious house fire 24 years later raises doubts. Josh Mankiewicz remembers the suspect who could not stop talking

An aspiring Playboy model is murdered in Miami, FL. A seven second clip of her last moments alive are caught on security video and could hold key clues. The haunting images make this case one of Dennis Murphy's most memorable.

A college student is found murdered and the case sits cold for nearly 40 years; Josh Mankiewicz reflects on the vow that keeps the case alive and the innovative method used to catch the killer.