cold case

American  

[kohld keys] / ˈkoʊld ˈkeɪs /

noun

1. a criminal investigation that has remained unsolved for an extended period of time.

   This year's award recipient is a state trooper whose work helped close a cold case from 1983.

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Etymology

Origin of cold case

First recorded in 1970–75

Example Sentences

In recent years, when a new break in a cold case makes headlines, it’s often because of updated genealogy tools or forensic detection technology.

From Slate • Apr. 6, 2026

Was there someone who ... was powerful who let him off the hook, and I just thought it was a good time to take a new look at it like a cold case detective would.

From Los Angeles Times • Mar. 30, 2026

"This prosecution and conviction some 27 years on from the original investigation shows the importance of cold case reviews and exploiting advances in technology," he said.

From BBC • Feb. 10, 2026

Last week, the Nanterre cold case unit launched a broader investigation into Pelicot's "criminal trajectories" to identify other possible crimes and victims.

From Barron's • Jan. 19, 2026

"A cold case is a case that hasn't been solved. My dad told me that while we were watching a mystery show on TV."

From "Scream for Ice Cream: Nancy Drew and the Clue Crew, #2" by Carolyn Keene