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

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

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.

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

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

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

A popular handyman in a New Hampshire town is found murdered and investigators follow forensic clues to a shocking conclusion.

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.

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.

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

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.

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