cold case
/koʊld keɪs/
Very CommonA criminal investigation that went inactive due to lack of evidence or leads, but was never officially closed.
Used both as a technical law enforcement term and casually in true crime communities. Online, it often implies the speaker has researched it and has opinions on what happened.
| # | Example | What it means | Source |
|---|---|---|---|
| 01 | this cold case from 1987 has been sitting unsolved for 35 years and the subreddit has better theories than the police did | Online communities have developed more detailed analysis of an old unsolved case than official investigators. | reddit, 2022 |
| 02 | they cracked a cold case from 1994 using a genealogy website. the technology is wild. | Genetic genealogy databases helped solve a decades-old murder. | x, 2023 |
| 03 | I fell down a rabbit hole on this cold case at 11pm and now it's 3am | Spending hours researching an unsolved crime without noticing the time passing. | tiktok, 2023 |
| 04 | the cold case files episode on this one actually missed the obvious suspect | Critiquing how a documentary covered an unsolved case. | reddit, 2022 |
Use it when
- Referring to an unsolved crime that investigators are no longer actively pursuing.
- Discussing a case that was dormant and then reopened.
- Talking about true crime cases that online communities research.
Do not use it when
- The case is still actively being investigated.Use “open case” instead.
- The case was solved and closed.
Cold case vs unsolved mystery
cold case
Cold case is a specific investigative status meaning police stopped actively working it.
unsolved-mystery
Unsolved mystery is broader and includes disappearances, unexplained events, and phenomena with no clear criminal angle.
Origin and context
Law enforcement terminology that entered mainstream use through procedural TV shows and true crime media. The term predates the internet but became heavily colloquial through the true crime podcast and documentary boom of the 2010s.
- First seen
- pre-2000s
- Confidence
- medium
Cite this page
Use this stable URL to reference the entry.
https://slang.fyi/cold-case