/ʌnˈsɒlvd kraɪm/ – Phrase
Definition: hành vi phạm tội chưa được khám phá.
A more thorough explanation: An unsolved crime refers to a criminal offense for which no individual has been identified, arrested, charged, prosecuted, or convicted, and for which the investigation has not led to a resolution or closure.
Example: The police are still investigating the unsolved crime that occurred last month.