[holding answer 19 June 2008]: Information on the number of crimes that have been detected using DNA subject sample profiles on the National DNA Database (NDNAD) taken from persons with no previous convictions is not available and could be obtained only at disproportionate cost. The NDNAD holds DNA profiles taken from persons arrested for a recordable offence but does not hold data on their criminal histories; this information is held on the Police National Computer (PNC).
Some research information is, however, available on the number of DNA profiles taken from those arrested but not charged and from those arrested, charged but not convicted of an offence that have resulted in a DNA match, thus providing the police with an intelligence link on the possible identity of the offender and assisting in the detection of crimes. In April 2004, an amendment to the Police and Criminal Evidence Act (PACE) 1984 came into effect which enabled the police to take and retain DNA and fingerprints from persons who had been arrested for a recordable offence. In the period April 2004 to December 2005, the retention of DNA profiles of arrested persons who had not been charged or proceeded against had resulted in matches with crime scene profiles from over 3,000 offences including 37 murders, 16 attempted murders and 90 rapes.
In May 2001, an amendment to PACE 1984 came into effect which enabled the police to retain DNA samples taken from persons who had been charged but not convicted of an offence. In the period May 2001 to December 2005, an estimated 200,000 DNA samples taken from people charged with offences had been retained on the NDNAD, which would previously have had to be removed because of the absence of a conviction. From these, approximately 8,500 profiles of individuals have been linked with crime scene profiles, involving nearly 14,000 offences. These offences included 114 murders, 55 attempted murders, 116 rapes, 68 sexual offences, 119 aggravated burglaries and 127 of the supply of controlled drugs.