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.

A hearing-impaired 77-year-old on a road trip is attacked by a thief and shot to death. Why? Because the man cannot hear his assailant’s demands. Random murders are among the hardest crimes to solve, but investigators are determined to bring this killer or killers to justice. Can advances in ballistics testing crack the case?

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

On a brutally cold winter night in 1984, a young woman is found viciously murdered on the side of a rural Wisconsin driveway. The victim, Traci Hammerberg, had been out with friends for a night of drinking and partying. What happened? Detectives initially have plenty of suspects, but the investigation would remain unsolved. Until nearly three decades later, when forensics from an unrelated crime helps breaks the case.

After a 79-year-old woman is found shot to death in her home, shell casings and a high-tech database reveal the unlikely killer.

When a beautiful college student is stabbed to death in her Knoxville apartment, suspicion immediately falls on her roommate. A bloody shoe print left by the killer exposes a murderer with no history of violence and no reason to kill.

The body of a 24-year-old criminology student is found wrapped in a blanket alongside a desolate Road in Brooklyn, New York. Police zero in on the bouncer at a SoHo bar.

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

Someone targets members of law enforcement in a peaceful Texas county. Numerous suspects emerge, and murders continue as detectives race against time. Finally, a single bullet casing uncovers the bizarre reason for which the killer wanted revenge.

An extremely successful California career woman keeps falling ill and doctors can’t determine why. When she dies, they still have no explanation, until they find a key figure in her life who has been lying about his past.

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

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 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.

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.

After the discovery of the brutal murder of an 18-year-old desk clerk of a beachfront condo, analysts use brand-new mitochondrial DNA technology to prove the killer's identity.

July 4th weekend leads to a tragedy for a California family. To catch a killer, detectives utilize an unorthodox technique—analyzing bug fragments—to help put a murderer behind bars.

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

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.

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.

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.

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.

In 1982, 37-year-old Navy lieutenant Lee Hartley is murdered while deployed out to sea. Cause of death? Arsenic poisoning. Investigators discover Lee had more than his fair share of enemies aboard the ship. But it takes years before investigators discover what really happened to Lee and who, ultimately, was behind this brutal murder.