14-year-old Tina Faelz is found stabbed to death on a popular shortcut from her high school to her home in the suburbs of Pleasanton, California. With no witnesses to the attack and no murder weapon, detectives have little to go on.

In 1980, radio intern Helene Pruszynski is found brutalized in a snowy field; after 37 years of fruitless leads, investigators tap into a public genealogy website that leads them across the country to the killer they've been hunting.

On Easter Sunday of 1992, the body of missing woman Lisa Ziegert is found in a field; the investigation yields many leads, but no true suspect; after more than two decades on ice, the case is revived when DNA phenotyping puts a face to the killer.

In late 1983, the bodies of five people abducted from a local fast food restaurant are found brutally murdered in an oil field. The main suspect is long believed to be a well-connected local man.

It's Christmas time in the tiny town of Chehalis, Washington. Friends and family of Ed and Minnie Maurin are expecting to attend the elderly couple's annual party, but when guests arrive at the Maurin house nobody is home.

When Zilphia and Reba Lowery's young nephew goes missing, the family is frantic. With little help from the police, who believe he is a runaway, they desperately search for clues. But things become even worse when Zilphia goes missing, too.

Brad Perry had recently returned from his Mormon mission, was going to school, and had just got engaged. His family never expected that when he went to work at his job as a gas station attendant they would never see him alive again.

Shortly after she became a widow, Anna Mae Florence's loving family moved her from Alabama to Columbus so she could be closer to her siblings and their children. But their good intentions turned to tragedy when she was brutally attacked in her home.

The longest running cold case of a law enforcement officer in the United States was the murder of Sheriff's Lt. Joe Clark.

On a hot July morning in 1989, Bob Siders, a single father in Newaygo, comes home from working the night shift at the local bottling plant. He finds that his daughter is not home. By early evening, Bob's worry turns to panic and he calls the police.

Near what's known as the hanging tree, the mutilated body of Timothy Coggins is found in late 1983; the investigation is thwarted and the case freezes for over 30 years, until a newly elected sheriff vows to bring the killers to justice.

Just after the last day of school in 1984, 15-year-old Reesa Trexler is found murdered in her grandparents' home; for decades, a stalled investigation only fuels the town rumor mill, pointing an accusing finger at Reesa's 13-year-old sister, Jodie.

In 1972, the body of Jody Loomis is found in the woods. Thirty-four years later, the killer's DNA is recovered from Jody's old clothing, but it isn't matched until 2018 when genetic genealogy helps point to one suspect.

Two masked gunmen commit a violent robbery and shoot Michael Temple Jr. in 2015, rendering him a quadriplegic for five years before his death. In this unusual cold case, DNA from a knife is used to create a sketch of the killer.