A family mourns the unexpected death of a beloved grandmother at Christmas, and while local police assure everyone that she was the victim of a tragic accident, some things about the scene don't add up.

Investigators think they know who killed a young woman, but the case goes cold. An amazing new forensic tool turns the cold case around.

A 33-year-old West Virginia husband and father seemingly dies in an accidental house fire; a closer look at the scene reveals a more sinister case.

In 1990, three sex workers are brutally murdered and left along the banks of the Spokane river. A serial killer was on the loose—and detectives had few clues. Animal hairs, fibers and a fingerprint were found, but for years the perp was never identified. More than 20 years later there’s a break in the case- and an arrest is finally made, but no one could have ever imagined who was behind this sinister crime.

A Texas love triangle turns deadly, and it appears to be an open-and-shut case until technology tells the tale.

When the 20-year-old clerk of an Atlanta-area smoke shop is gunned down during a robbery, investigators use a videotaped confession to smoke out the killers.

A fire leads investigators to re-examine an unusual death, which meant digging up the victim who had been buried for years.

The body of a young woman is discovered in a remote area, leading forensic investigators on a search for clues to identify her and her killer.

Cell phone forensics help investigators solve a murder in an upscale community.

A murder victim’s final moments are caught on tape; the crime scene looks like a clear robbery-murder. Text evidence at first points to a jilted lover. Soon, police identify a second suspect with a possible motive of deadly revenge. Forensic technology and DNA evidence combine in an attempt to make the case.

A true-crime enthusiast may connect a Jane Doe to a missing persons case in Ohio.

A young Colorado mother suddenly vanishes on Thanksgiving, but when police trace her cell phone, it leads them to a surprising character with an even more surprising story.

Investigators search for clues after a body is discovered in a Florida waterway.

A deeply religious librarian, wife and mother named Gail Fulton is shot execution style in the quiet suburbs of Michigan. Surveillance video reveals it was trio of killers that took her down. Eventually, detectives get a break: a handwritten note. But will it provide enough clues to catch the mastermind behind this horrific killing?

He is a criminally charged sex offender and a murderer who attacks in a terrifying rage. This predator manages to evade capture for years, but he leaves a critical piece of evidence behind – his palm print. Detectives are determined to do whatever it takes to put a name and a face to the print.

A woman is killed in a crowded parking lot in the middle of the day. It looks like a professional hit, but evidence unveils an elaborate plan.

51-year-old father and teacher Bill Sparkman is found hanging naked from a tree with the letters “FED” scrawled on his chest. With barely any evidence to work with, investigators turn to these letters for answers… which leads to a surprising conclusion that no one saw coming.

A single mom looking for love vanishes without a trace. Foul play is tragically confirmed when a large pickup truck toolbox opens to her body stuffed inside. Homicide detectives investigate men she matched on dating sites, another man she met at work, and finally, a lover with a secret and violent past.

Eight days after she had disappeared on her way to a family ski trip, an 18-year-old young woman's partially nude body is found floating in a river in Wyoming. Years later, DNA technology uncovers dark secrets that led to her demise.

After a young mom is found brutally murdered in her home, investigators find startling clues on her cellphone that could lead to her killer.

The murder of a young teacher’s aide leaves a hole in the heart of her small community in Agawam, MA. As the rumor-mill about suspects churned, the actual perpetrator slips further away. But, generations of investigators and a scientific breakthrough leads to a shocking end to a tragic case.

An upscale apparel store in Bethesda, MD, is the site of a gruesome scene when an employee is killed and her co-worker is battered and tied up, but surveillance video and blood evidence shed further light on the crime.

California police are baffled when an innocent man's DNA is found at the scene of a deadly home invasion, and authorities team with the man's defense attorney.

A young mother is found murdered in her home and there are two suspects with ample motive, but an unusual interview and security camera footage have investigators puzzled.

When a Yale student mysteriously vanishes days before her wedding, investigators comb a secure research lab for evidence.