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.

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.

This series delves into the psychological showdown that takes place inside actual police interrogation rooms and dissects what happens to yield a confession. Each hourlong episode takes viewers through the twists and turns of a real homicide case, from the crime scene to the suspects' questioning to the ultimate confession. The police officers and detectives assigned to each case reveal their methodology while interviews with the suspects' and victims' friends and family shed light on the crime. In every case, the interrogating officer will "break" the suspect and get a shocking reveal of what really happened.

In "She Made Me Do It," women are the supposed masterminds behind deadly acts but aren't necessarily the ones accused of the crimes. As is customary with these types of shows, witness testimony, interviews with experts and dramatic re-enactments are used to tell the story of each case. Viewers get both sides of the story in each case before finding out the jury's verdict. Romance is often at the core of the attacks.

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.

"Killer Couples" is in the same vein of the long-running true-crime series "Snapped," which tells stories of people who commit murder or attempt murder, but with a focus on couples who commit crimes. Using re-creations and firsthand accounts, each episode digs into a case, telling the story of the couple's romance, how the relationship evolved from love to manipulation, and what ultimately led the couple to commit the crime. The stories range from teenage lovers who go on a multistate crime spree to lesbian lovers who want to eliminate one of their husbands.

"Murdered by Morning" showcases stories where individuals are unaware that the night in question will be their last. From a girls-night-out gone bad to an overnight shift at a local toy store that takes an unexpected turn, the series recounts how an average night can quickly turn into a nightmare. By examining each case step-by-step, the series combs through numerous suspects until the killer is eventually caught.

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.

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.