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.

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?

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.

A Texas ex-con resolves to live a clean life after his release from prison. When he’s later arrested and convicted for a bloody murder, he insists he’s innocent. From behind bars, he’s determined to use forensic science to prove his case.

Patients at the VA hospital in Clarksburg, WV, keep dying after experiencing shockingly low blood sugar levels. An investigation into their deaths reveals the patients were injected with lethal doses of insulin.

A young single mother is abducted from a gas station and later found stabbed to death near an oil field. Detectives use shoe and tire impressions to weed out numerous suspects and find the killer.

In the story of a Los Angeles kidnapping, ransom and murder ring, retired scientists use sonar equipment to locate victims at the bottom of a reservoir.

An Illinois mother and her two young children are brutally murdered in their beds. Lurid threats are spray-painted all over the walls of the crime scene. Detectives discover death threats sent to the family, exposing an unlikely killer.

A young Texas teenager and her boyfriend are brutally attacked on Valentine’s Day; she is found dead while her boyfriend escapes. The case goes cold for nearly 50 years before a new forensic test exposes a family man with a dark secret.

A 70-year-old retired veteran is found dead on his boat after a bad sea storm. Detectives discover he was killed during an attempted robbery after winning $400 in keno.

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

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

Police make a shocking discovery when they open a suitcase found floating in a bay.

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.

Police race to find a serial killer terrorizing a small Texas town.

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

After the brutal slaying of a young couple on a road trip, the victims' families begin receiving disturbing letters.

The unexpected and mysterious death of a health-conscious woman triggers an investigation into what killed her.

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

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 small community is shocked when a woman is shot and killed in a church. Police are left with few pieces of evidence and no suspects.

An insurance agent is shot execution style in his office in broad daylight, but the killer left no fingerprints and there was no murder weapon found at the scene… Then, investigators discover a critical clue invisible to the naked eye that cracks the case. (also marked as S1:E12)

A healthy, young mother mysteriously dies after a minor traffic accident triggering an investigation to find out what caused her death.

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

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.