uløste mord
A murder case in which the perpetrator has not been identified, apprehended, or successfully prosecuted. Not a distinct legal category under federal law, but a descriptive term used in criminal investigations and true crime literature.

Definition
An unsolved murder refers to a homicide case that remains open because law enforcement has been unable to identify the offender, make an arrest, or secure a conviction. This is a practical investigative classification rather than a formal legal designation under federal criminal statutes.
Under federal law, murder is defined in 18 U.S.C. § 1111 as the unlawful killing of a human being with malice aforethought. The statute distinguishes between first-degree murder, which involves premeditation or occurs during the commission of certain felonies, and second-degree murder, which encompasses all other murders with malice aforethought. However, the legal definition of murder itself does not address whether a case is solved or unsolved—that determination is purely investigative.
A murder becomes classified as unsolved when the investigation fails to produce sufficient evidence to identify a suspect, when identified suspects cannot be located or apprehended, or when available evidence is insufficient to support prosecution. Law enforcement agencies typically keep these cases open indefinitely, as there is no statute of limitations for murder prosecutions under federal law or in most state jurisdictions.
In true crime contexts, unsolved murders often attract public attention and amateur investigation efforts, particularly in cases involving unusual circumstances, multiple victims, or extended time periods without resolution. The term encompasses both cold cases—older investigations that have gone inactive due to exhausted leads—and active ongoing investigations where the perpetrator remains unknown.
