Three members of a church-going family are killed in a triple murder in Lancaster, Pa.

As police search for missing 16-year-old Kathey Horn, they uncover an underworld in their majestic town of Traverse City, Mich., filled with nomadic hippies, witches and cults.

The murder of Dennis and Norma Woodruff in their rural Texas home sends shock waves through the town.

Police suspect foul play after high school sophomore Kiplyn Davis fails to return home from school.

In Rock Hill, S.C., former homecoming queen Melinda Snyder's murder embroils the town in a mystery that won't be settled until the South Carolina Supreme Court weighs in.

When Veronica Bozza's body is found on her living room floor, it sends shock waves through the close-knit community of Bridgewater, Tenn., and leads investigators to uncover a bizarre murder plot right out of a Hollywood movie.

After John Kowalczyk is shot dead, his friends cannot imagine who would murder the successful entrepreneur, but suspects emerge as police begin to look at Kowalczyk's inner circle.

When 18-year-old college freshman Katherine Foster goes missing, rumors fly as fellow students at the University of South Alabama fear the worst.

Jimmy McClain is a teacher and coach at a Tennessee high school, then he is found assassinated in his home, and police must contend with a laundry list of suspects.

Speculation and rumors fly when 16-year-old best friends Dawn Donaldson and Crissy Campbell vanish overnight and detectives must uncover the truth behind their disappearance.

Shelley Nance is found stabbed to death, shocking the community of Lake Highlands, Texas, then her friends are stunned as police zero in on them, uncovering a case of fatal attraction.

In Roswell, Ga., millionaire Lance Herndon is living the American dream, then he is found brutally murdered, and investigators must untangle a twisted web behind the gates of the town's upscale communities.

After business owner Michael Zammitti Jr. is found shot to death at his desk, police must untangle a web of lies and corruption that will rock two New England towns.

When Staff Sgt. Michael Severance goes AWOL, the community of San Angelo, Texas, rallies around his bride, then investigators discover a sinister side to his disappearance, uncovering a saga of treachery and passion as big as the state of Texas.

In Macon, Ga., Mercer Law School graduate Lauren Giddings goes missing, and police search her apartment complex, finding a human torso in a trash bin.

In Omaha, Neb., stage actress Pasinetta Prince is found strangled to death in her home; police draw up a long list of admirers who are possible suspects.

In Norris, Ill., Jessica Evans and Jacob Wheeler never return home after going fishing, then Wheeler's abandoned pickup truck is found with a body in its bed.

In Monrovia, Md., Debbie Fagan is found shot to death in her car, leading detectives to uncover a web of lies and deceit as they dig into her past to find out who would want to murder the loving mother of two.

In Hanover, Pa., townspeople are shocked when kindly 55-year-old Monica Schmeyer is found shot to death in her living room.

In Orlando, a mysterious call to the sheriff's office draws investigators to a second floor apartment where a young woman has been brutally beaten.

The murder of Christopher Green sends shivers up citizens' spines in the small, snowbound city of Bangor, Mich., and detectives follow the clues down a path to a chilling outcome.

Dark dreams see the light of day in "Your Worst Nightmare," a typical Investigation Discovery true-crime series complete with jump-out-of-your-seat moments and chilling conclusions. Classic suspense film techniques highlight re-enactments of creepy, harrowing crimes, as victims' darkest dreams become unfathomable realities. Each hourlong episode features one story interlaced with commentary from law enforcement, criminal justice professionals, and psychologists, plus accounts from friends and family of the victim.

From the outside, families seem like harmonious units in loving homes. But you don't necessarily know what secrets families are hiding from the outside world. This series, narrated by actress Brenda Strong, explores families hiding the most extreme of family secrets: murder. Each episode explores a death in a family, unraveling the motives of the family members, all of whom are potential suspects -- and potential victims. Sibling rivalries, disputes over family businesses and infidelity are some of the factors that lead to the families' ultimate betrayals.

Veteran journalist Paula Zahn steps out of the studio and into the field to unravel criminal investigations, tracking the drama of each story by featuring the opinions of those closest to the case, including law enforcement officials, the families of the victims and the incarcerated, lawyers from both sides, and first-time TV interviews with convicted murderers.

From blushing brides turned cold-blooded killers to smitten grooms with shocking dark sides, "Fatal Vows" examines the criminal psychology behind deadly divorces. Guiding viewers through actual stories of love gone wrong are psychotherapist Stacy Kaiser and forensic/clinical psychologist Dr. Brian Russell, who examine each couple to better understand how the marriage turned from flawed to fatal. Stylized re-enactments are supported by interviews with family, friends, law enforcement, and potential victims of the crime, while Kaiser and Dr. Russell provide analysis on unions that break down until divorce and murder collide.

Actual murder cases from the 1950s and '60s get sleek, cinematic treatment in this series, transporting viewers back to a pre-forensics era when sometimes it was more about how suspects looked than what they did that determined guilt. Narrative by a fictional bystander -- who "knew" the victim -- drives the hourlong episodes, while reporters who covered the case explain how the events impacted society. Artfully crafted re-creations play out like period thrillers, staying true to fashions and styles, while spotlighting cultural taboos and social norms surrounding each case.

Chilling scenarios unfold in this true-crime series, which tells actual stories of people who shared their lives with loved ones who became killers. Each hourlong episode puts viewers in the shoes of the loved one, who first notices that something is amiss, interprets the puzzling signs and clues, and eventually comes face-to-face with the horrible truth: that the person has a very dark side. Exclusive interviews and firsthand accounts of the critical moments leading up to the vicious acts showcase devastating, often undiscussed consequences on the people who have nurtured, loved and raised a murderer.

Here today, gone tomorrow. Thousands of people go missing in the United States each year, leaving behind only a mystery without any clues. Their stories are told in "Disappeared" through the voices of family, friends and investigators trying to solve the case, with each hourlong episode recounting the final stages that led to a person's disappearance. Interviews with experts including psychologists and forensic specialists provide new insights into what may have happened -- whether foul play was involved or the subject simply ran away.

Lt. Joe Kenda spent 23 years in the Colorado Springs Police Department, where he amassed a lifetime of memories catching killers and helping solve close to 400 homicide investigations. The vivid memories are brought back to life in this hourlong series, as Kenda reopens his "Murder Books" for viewers -- folders in which every detail of his murder cases is held -- to revisit the most disturbing cases still haunting him today. As he details the process of how he solved the crimes, Kendra also embarks on a personal journey, coming to terms with long-suppressed nightmares. As he says, "I don't want to tell these stories. I need to."