Dateline: Secrets Uncovered

A graduation party ends with a man's death and leaves two teenagers facing a long fight for justice.

The fire breaks out before dawn; after the smoke clears, a mother of two young children is found dead; it's the tragic end to a life that held so much promise, but for investigators, it is just the beginning.

Kevin and Morgan Mengel are happy at first, but when the marriage goes bad, he goes missing; police wonder if he simply left, but a family's relentless pursuit leads to a stunning confrontation and, eventually, the truth.

A family mourns the loss of a young mother in a house fire; authorities rule it an accident; years later, there is another accident and second loved one gone; investigating if this just a string of bad luck or the work of a calculating killer.

On Nantucket Island, Mass., a couple's connection is instantaneous, but their summer romance takes a tragic turn; it seems like an open-and-shut case, but there's a surprise in store.

A man makes a frantic call to 911 after finding his wife dead in a bathtub, but the couple's daughters lead police to investigate their father.

It is a story of obsession that boiled over into a brutal crime. Right away, one woman said she knew what happened. Yet, it took years to bring the alleged killer to trial and the verdict was far from the end of this case.

Aasha Davis moves to Hollywood with big dreams; her sister Lesley follows for support; Lesley goes missing and Aasha is desperate to find her; in a town built on deception, the police come up with a high-stakes plan to smoke out their suspect.

It is just before Halloween; Joel Lovelien and his fiancé head to a local bar packed with people in costume; Joel steps outside and walks into a troubling mystery.

Keith Reed is a highly-regarded school superintendent; when he doesn't show up at an out-of-town conference, it sets off alarm bells; investigators take a hard look at his love life for clues and make a startling discovery.

Kelli Bordeaux is just starting what she hopes to be a long career in the military, but fate has other plans; when she vanishes, friends and family launch a frantic search, but it is a stranger hell-bent on justice who uncovers the ugly truth.

Sandra Galas was born and raised in paradise; police investigate two men in Sandra's life, but the case goes cold; her father refuses to give up, relentlessly pursuing the truth for more than a decade.

Diane McIver was a successful businesswoman who enjoyed a lavish lifestyle with her husband. Then she was gone. It was a mystery riddled with privilege and power, but investigators needed to answer a crucial question: was this an accident or murder?

Divorced mother Joan Lockwood is excited about the next chapter in her life, then five gunshots shatter her plans.

Detectives believed two young children witnessed the brutal murder of their mother; the prosecution builds their case around what they thought those kids observed, but another version of events may be possible.

A story of teens, text messages and a convoluted search for the truth; Conrad Roy, who had shared a secret with someone close to him, had vanished.

Amanda Lindhout was a journalist braving the world's most dangerous hotspots. Then, she became the story. What she endured from her captors was terrifying. Years later they found her again and secret agents put a daring undercover sting into action.

For over a decade, El Chapo evaded authorities but one man was determined to catch the infamous kingpin; Former DEA agent Andrew Hogan comes out of the shadows to detail his search and capture with never-before-seen videos and photographs.

Angel's Landing was a community of free-spirits with Lou Castro at its center; Investigators suspicious of the mysterious deaths happening there; commune members have courageously decided to tell their stories in hopes of helping others.

Churchgoing mom shot at point-blank range in her garage; saving her would take a miracle and investigators want to know if this crime was random or if someone wanted her dead.

In the still of the night, strangers armed with knives destroy the lives built by a hardworking man and his doting wife.

A young mother who is pregnant with her second child is gunned down on her way to work; her sisters become amateur detectives to help find her killer.

Pizza deliveryman Brian Wells robs a bank with a bomb strapped around his neck, launching one of the strangest cases ever investigated by the FBI.

A bank executive tries to rob his own bank; investigators think it's an inside job but eventually learn the crime is connected to a spree carried out by men who managed to keep their identities secret, praying on people who did the opposite.