A high school senior is murdered in her family's Minnesota farmhouse, but the case soon goes cold; years later, a fresh set of eyes spots an overlooked clue, but cold case detectives will need more to convict the killer.

The mutilated body of 17-year-old Lori Billingsley is found in a ditch on the outskirts of town, pointing to a sadistic killer on the loose in Oregon, but Billingsley's case goes cold, and it's up to her sister to pursue justice.

In southern Louisiana, a task force forms to hunt for a serial killer following a series of deadly home invasions.

A New Hampshire man is shot dead through his screen door; investigators are stumped until they uncover a seething grudge and a culprit closer to home than anyone could have imagined.

After a respected widow is beaten to death in her Salt Lake City home, investigators suspect she knew her killer, but it will take 20 years before a set of children's fingerprints can put him at the scene of the crime.

When 18-year-old Lisa Monza is murdered in San Lorenzo, Calif., investigators look for a connection to other unsolved murders in the area.

After the blood-soaked body of a young woman is found on the floor of her apartment in Orlando, Fla., it's up to investigators to find her killer before he strikes again.

Debra Dill's bludgeoned body is discovered next to her car on a September morning in 1973, and it will take nearly two decades to put her killer behind bars.

Kimberly Dunkin's body is found with a single gunshot wound to the head, and though investigators suspect she was the victim of gang violence, it will take 15 years, a deck of playing cards and a lucky break before the case breaks.

Matthew Monahon returns home to discover his pregnant wife, Kelsey, hogtied on the floor and clinging to life, then she dies a few days later, and a $300,000 life insurance policy surfaces, turning Monahon into the number one suspect.

The dumping of a woman's body prompts detectives to begin connecting the dots and find the link between seemingly random beatings, carjackings and murders.

In Oregon, 19-year-old college student Brooke Wilberger, a devout Mormon, is abducted from a parking lot in broad daylight, prompting a massive search that grabs headlines across the country.

Years after a woman is shot and the case goes cold, news of a potential prison confession leads investigators back to her front door.

On her last day of school, a 14-year-old girl is brutally beaten and set on fire, sending shock waves through her California community.

In Cleveland, 14-year-old Gloria Pointer is snatched off the street, assaulted and murdered on her way to school, and it will take detectives nearly 30 years to put her killer behind bars.

In Iowa, a pregnant 23-year-old woman is shot in her own bed, and investigators must determine if they are looking for someone with a deadly grudge or a culprit closer to home.

A college student is stabbed to death while working the nightshift at a convenience store, and her murder goes unsolved for 10 years until an informant steps forward.

Washington authorities are stunned when a mother of three dies from cyanide poisoning, and their murder investigation uncovers a pattern of tampering with boxes and blister packs.

After the mutilated body of 17-year-old Shauna Card is discovered on the bathroom floor in her Orlando, Fla., home, it will take years for investigators to finally crack the case.

When a 20-year-old woman is gunned down in a Maryland suburb, the case goes cold with few leads and almost no evidence, and it will take 25 years before investigators finally close in on the killer.

In Kilgore, Texas, the residents are reeling from the execution-style slaying of five people abducted from a fast-food restaurant, and it will take several decades before the perpetrators are brought to justice.

Solving a murder case is like completing a jigsaw puzzle, and the more pieces there are, the more complicated it can get. "Motives and Murders" tips its cap to the puzzle solvers of the law enforcement world, the criminal investigators who go to great lengths to bring notorious killers to justice. The one-hour episodes reveal the kinds of challenges, setbacks and dramatic revelations that detectives encounter to close complex, nontraditional homicide cases.

"Cold Blood" gives viewers a chance to examine the evidence of a real homicide case for themselves by bringing the cameras to the scene of the crime. The series evaluates the evidence and tests opposing theories by demonstrating what might have happened in the events leading up to the crime from a variety of angles. Each episode showcases one homicide case, following it from the collection of forensic evidence through all stages of the investigation until clever detective work and state-of-the-art forensic science reveal the truth.

As Olivia Benson on "Law & Order: Special Victims Unit," Mariska Hargitay has earned rave reviews for her passionate portrayal of a female detective who deals with disturbing cases. Homicide police work is a gritty job mostly filled by men, but this TLC series salutes women who are dedicated to solving murder investigations. The focus is on three detectives working in Atlanta and Cincinnati, with cameras recording their relentless determination to bring closure to victims' families by pursuing the truth and putting the guilty behind bars. The detectives are Summer Benton, a five-year veteran of the Atlanta Police Department's homicide division; Jenny Luke, who has solved 70 cases for the city of Cincinnati; and Jennifer Mitsch, a member of the Cincinnati Police Department for 16 years, the last eight in homicide.

Uncovering the dark and twisted motives that led to gruesome killings in the pursuit of a deeper understanding of the relationships behind the horrific killings and of the psychology of the people who committed them.

When a crime scene throws suspicion in multiple directions, investigators may have a perfect murder on their hands. Ingenious killers are every detective's worst nightmare, as the crimes they commit are full of leads that become dead ends, and multiple suspects are ultimately discarded. But just when a murderer thinks he or she has successfully gotten away with it, one small clue leads to another and a cold case suddenly turns hot. "The Perfect Murder" follows actual cases and uses stylized re-enactments depicting detectives slowly putting the pieces together to complete intricate puzzles.

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.

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.

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.

"Relentless With Kate Snow" takes viewers on an emotional journey with grieving families as they work tirelessly, often putting their own lives in danger, to find the culprits responsible for the deaths of those they loved most. Their relentless pursuit of justice paired with the opportunity to work alongside law enforcement creates a powerful and dynamic force that won't rest until due process is served. From a mother dedicated to putting her son's killer behind bars after he's gunned down at a recording studio to a 20-year search for a victim's killer that was so aggressive it transformed an unsolved, cold case into an active investigation, the series reveals gripping firsthand accounts from the families who will stop at nothing to get the justice the victims deserve.