A small child is the only witness to a terrible crime: the murder of her mother. But investigators say they can't rely on her testimony because she is just a toddler. Will her memories prove true and bring a killer to justice?

A young woman feels lucky to have a second chance: After a failed marriage, she was back together with the man she'd loved since high school. That is, until one morning, when a single shot rang out in a parking garage. What happened to Ed Schiller?

When a well-liked young man lost his wife and son on a family outing, an entire town mourned. But there was somebody who suspected the tragedy was no accident. But will a widower's best friend come forward and accuse him of causing his family to fall over a cliff?

See images of Bob Duke, convicted of murdering his wife, Liana, and five-year-old son, Erik. The two plunged to their deaths off a cliff.

Her name was Christie, and she was just 25 when she was found murdered in her home. But with few clues, the case soon grew cold. No evidence stuck out at the crime scene except for a burnt cigarette. Was it left behind by her killer?

Detectives play the role of Cagney and Lacey in a cold-case murder where the key evidence is a burned-down cigarette. But the real closer in this 20-year-old case is the victim herself, from beyond the grave. See it Friday, Oct. 22 at 9 p.m. ET, 8 p.m. CT on Dateline NBC.(Dateline NBC)

Family pictures and evidence photos in the murder of Christie Fleming, a 25-year-old woman who was murdered in her own condo in 1989. Fourteen years later, Arturo Gutierrez, a former boyfriend of Fleming's, was convicted in the case.

Find out the secrets and symbolism that lie in the most unexpected parts of our nations capital in Matt Lauers exclusive interview with Dan Brown, author of "The Lost Symbol," the follow-up to "The Da Vinci Code."

He came out of the woods, in the night, in the rain. Over 14 years, more than a dozen women were raped in their own homes by a stranger who terrorized a Tennessee neighborhood, leaving no clues except for one.

It was the anwer to a mother's prayers: Jaycee Dugard, kidnapped at age 11, was found alive. But why did it take 18 years to find her? And what could have been done to stop her alleged kidnapper sooner? Dateline investigates.