Information is not collected centrally from police forces on the number and proportion of unsolved crimes for which the investigation has been closed.
However, since April 2002 records have been captured on the national DNA database (NDNAD) match reporting management information database (MID) on matches between crime scene sample profiles and subject sample profiles.
The figures provided are estimates as it is possible that some crime scene profiles were matched before 2002 and therefore not captured on the MID. The number of unmatched crime scene profiles may therefore be lower than indicated. It is also important to note that although a crime scene sample profile on the database has not matched to a subject sample profile, the crime may have been detected through other evidence.
The data provided are management information and have not been formally assessed for compliance with the Code of Practice for Official Statistics.