A team of retired detectives investigates the 2005 death of a man who was found in a rural Michigan lake 21 days after he went missing; with little decomposition to the body, the team believes the death could be the work of the Smiley Face Killers.

A team of retired detectives investigate the 2008 death of a young man in a Philadelphia suburb who was found 14 days after he went missing in an area that had been searched; the team believes his death could be related to the Smiley Face Killers.

A team of retired detectives investigate the death of a college honors student who disappeared in Chicago on the Eve of Y2K and was found on a beach in Indiana 77 days later; the team believes the case could be related to the Smiley Face Killers.

A team of retired detectives travels to Boston to investigate the 2009 death of a young Navy veteran; the victim's girlfriend spoke to him just minutes before he vanished and the team believes his death could be the work of the Smiley Face Killers.

A team of retired detectives travels to La Crosse, Wisconsin, to investigate the 2006 death of a college basketball player; they believe La Crosse is ground zero for their Smiley Face Killer theory with multiple drowning deaths of college-aged men.

A team of retired detectives investigate the mysterious 2017 drowning death of a graduate student in Pittsburgh and explore whether the case is connected to the Smiley Face Killer theory they've been investigating for the past decade.

Each episode of this true-crime reality series examines a different felon, usually a female, who has committed murder or attempted murder. The victim is usually the perpetrator's partner. The documentary-style series features interviews with friends and family members of the accused and victims, law-enforcement officials, attorneys and other people with first-hand knowledge of the cases.

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.

The holiday season between Thanksgiving and New Year's is often thought of as a celebratory period to spend time with friends and family. That is not always the case, though, as the period is not immune from experiencing the same types of violent crimes that occur throughout the year. This series documents stories of tragedy that struck during the holidays, with firsthand accounts from people who had friends or family members killed during the joyous time. Sometimes the victim is killed by someone close to them, such as a case of sibling rivalry turned deadly, but sometimes the killing is done by a stranger who interrupts a holiday gathering with gunfire.

Award-winning Israeli filmmaker Avi Belkin examines an unsolved, mysterious death in the American heartland and the corrosive effects of vigilantism. In a case garnering international attention in the early 1980s, "town bully" Ken Rex McElroy is shot dead in front of almost 60 people in Skidmore, Mo. As local and federal investigations ensue, witnesses to the crime continue to deny having seen anything. The code of silence that envelops the tiny town changes the lives of its residents forever, as additional violent incidents plague the isolated community in the years that follow.

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."

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.

Some of the world's most notorious murders are the subject of "It Takes a Killer," which investigates the crimes from the perspective of the killers, trying to get inside their minds and determine their motives. Leading homicide investigators and experts from such agencies as the FBI and Scotland Yard take a look at the evidence pulled from crime scenes and profile the killer's behavior to try to piece together the details of each murder, explaining when, why and how each criminal committed the crime. For the wannabe detectives watching the show, the experts also reveal how the crime was solved -- which often requires authorities to think like a killer.

There's a reason murder investigations don't begin with preconceived notions. Sometimes those least expected to be capable of committing such dark deeds -- respected role models and trusted members of the community -- can have a sinister side. "Unusual Suspects" documents baffling, challenging investigations, actual cases that were anything but cut and dry. Episodes feature in-depth interviews with leading law enforcement personnel combined with stylized re-enactments, illustrating how illusive offenders evaded capture for years before being undone by persistent police work.

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.