The case of youthful con man Edgardo Perez, who allegedly preyed on older men until it turned deadly; Callahan Walsh travels to Boulder where teenage babysitter Chris Deininger confessed to abusing 29 kids in his care before fleeing.

John Walsh investigates the accusation that Lamont Stephenson strangled his fiancé and her dog; Callahan Walsh explores police claims that Gloria Schulze is a drunk driver who repeatedly cheats the legal system.

Salvador Vaca Garcia makes a tearful appearance on local news after his girlfriend disappears; Callahan Walsh looks at Brian Keith Freeman who allegedly slit his fiancé's throat when their engagement fell apart.

Luis Frias makes John Walsh's most-wanted list after allegedly stabbing his common-law wife to death in front of their children; Callahan Walsh explores the case of Harold Butch Knight, who left a trail of clues after confessing to killing his wife.

John Walsh profiles triple homicide suspect Mike Bullinger who led a double life; Callahan Walsh looks at the case of Tomas Magallon Gonzalez, who allegedly sexually abused his stepdaughter for years before taking her life.

John Walsh investigates Alicia Osibin who is wanted in connection with the shooting death of her elderly mother; Callahan Walsh speaks to Andrea, an alleged victim of Frederick McLean's abuse, who is still desperate for McLean's capture.

John Walsh profiles Juan Lazaro Abrego who is believed to have murdered his ex-girlfriend, a beloved schoolteacher; Callahan Walsh investigates Derek Dean, a St. Louis man accused of shooting identical twins, killing one and wounding the other.

John Walsh tracks the story of convicted killer Glen Stark Chambers, who beat his young girlfriend to death and then escaped prison twice; Callahan Walsh investigates a murder suspect who eludes capture for 20 years.

John Walsh investigates how Eric Jones, the son of a preacher, allegedly turned to murder; Callahan Walsh tries to make sense of how a dispute over a dog could provoke Ricardo Villanueva Cordova to reportedly commit murder in broad daylight.

John Walsh spotlights Jihad Ramadan who allegedly stabbed a fellow university student to death; Callahan Walsh looks for Thayne Smika who reportedly shot his roommate in cold blood over back rent.

John Walsh profiles John Blauvelt, a troubled U.S. Army veteran who is accused of waging war against his young wife; Callahan Walsh looks at Rudy Fernandez, whose romance with his high school sweetheart is believed to have turned deadly.

John Walsh reveals that a single mother is far from safe with ex-Marine Raymond R.J. McLeod who initially seemed like a knight in shining armor; Callahan Walsh discovers how rapper Maurice Nesbitt's constant abuse of his girlfriend turns deadly.

Victims' rights activist John Walsh returns to weekly TV as host of a documentary-style investigation series. Walsh details stories of ongoing cases involving fugitives, with the intent of expanding searches outside the United States. Interviews with victims, loved ones and law enforcement accompany new leads in each hourlong episode, giving the public information to facilitate the capture of suspects. Walsh, a spokesman for the National Center for Missing & Exploited Children, hosted the series "America's Most Wanted" for 25 years, helping apprehend more than 1,200 criminals.

In this eight-episode series, viewers hear directly from detectives who investigated cases that haunt them to this day. These true-crime stories -- from mysterious vanishings to twisted family murders -- are the "unforgettable cases that disrupt law and order, and keep authorities up at night," says Investigation Discovery.

Like a pane of glass cracking in all directions before shattering, the impact of a single crime can create ripple effects that forever alter multiple lives. This Investigation Discovery series unravels actual homicide cases to explore how the past continues to haunt the present for those involved -- loved ones, witnesses, and law enforcement. Each episode is structured around three distinct perspectives of the same crime, and as viewers learn different details by way of first-person interviews and stylized re-enactments, stories, which at first seem random, slowly start to intertwine.

Crime author and investigator Jax Miller and former police investigator Sarah Cailean tackle a mystery that has stumped authorities for nearly two decades -- the confounding cold case of Lauria Bible and Ashley Freeman, two Oklahoma teenagers who disappeared in December 1999 after the Freeman family trailer was burned to the ground. In the four-part documentary series, the investigators delve into the many strange theories of the case and unravel a much larger story of unsolved murder, allegations of cover-up and corruption, and a truth that proves even more incredible.

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.

What lurks in the shadows during graveyard shifts comes to light in this series, a quintessential Investigation Discovery offering that features nail-biting re-enactments of actual crimes in which darkness hides predators hungry for a midnight snack. Told through interviews with victims' family members and law enforcement, each story begins after a brutal crime is committed in the quiet of the night, and community members are left wondering who might be next. Investigators get to work, knowing that each time the sun sets, the body count might rise.

"Murder for Hire" gives an exclusive look into the dark world of contract killings, showcasing some of the most fascinating murder for hire cases ever caught on tape. In an alarming trend, investigators are seeing a sharp increase in hired hits across the country, and those attempting shockingly include: housewives, wealthy bankers, military officers and even grandmothers. From scorned lovers to jealous relatives, the show explores in rare, never-before-seen footage, how a seemingly good relationship can go wrong and the emotions surrounding the reveal when an intended victim discovers a hit has been taken on their life. Each standalone episode features a different case of undercover agents immersing viewers into the real-life sting and investigation as they attempt to catch the perpetrator and ultimately prevent a murder.

Think "Cold Case" meets "CSI" with a bit of "Rizzoli & Isles" mixed in, then make it real. That's the formula for this unscripted procedural drama that follows two veteran female investigators as they attempt to crack murder cases that have lingered for years without answers and closure. Kelly Siegler is an attorney and former Texas prosecutor who successfully tried 68 murder cases in her 21 years on the job, including 20 capital murder death penalty cases in which she secured the death penalty in 19 of those trials. She gets help from veteran detectives, who dig into small-town murder cases that have gone unsolved for years in the hope of getting justice for the victims and their loved ones.