Cold case refers to a crime or an accident that has not yet been solved to the full and is not the subject of a recent criminal investigation.
It is possible that in some cases new information could emerge from new witness testimony, re-examined archives, retained material evidence, as well as fresh activities of the suspect. New technical methods developed after the case can be used on the surviving evidence to re-analyze the causes, often with conclusive results.
One of the most famous cold cases, the Tim Masters case, has been re-investigated by IFS. With new DNA techniques IFS was able to prove that Tim Masters was innocent and this ultimately let to the release of Tim Masters who served a lifetime imprisonment without parole.