§ Ms Blears
It is not possible to provide figures for the number of crimes that have been solved by the use of forensic science as convictions are achieved through integrated criminal investigation and not by forensic science alone. The contribution that forensic science makes to criminal investigation has been assessed separately for:
- (a) DNA analysis
- (b) non-DNA analysis (for example toxicology and analysis of trace evidence such as fibres, glass etc.).
The Home Office collects data on the number of crimes that have been detected, where DNA match report was available. However, it is important to note that the availability of DNA intelligence in the crime may not have been causal in solving the crime.
The total number of crimes in which a DNA match report was available that were detected for police forces in England and Wales were as follows:
Number of crimes in which a DNA match was available 2000–01 14,785 2001–02 15,894 2002–03 21,098
No data are available on "DNA detections" for each FSS laboratory.
(a) Non-DNA analysis
The contribution of forensic science in the provision of both intelligence and evidence to criminal investigations has been evaluated internally by the Forensic Science Service (FSS). Such assessment is based on the number of cases where the FSS has judged its contribution to be effective. This information has only been recorded from April 2003-January 2004 inclusive, and is set out for each FSS laboratory in the table following.
FSS laboratory Number of evidential cases where the FSS has judged its contribution to be effective Number of intelligence cases where the FSS has judged its contribution to be effective Birmingham 3,030 19,536 Chepstow 1,741 238 Chorley 3,680 768 Huntingdon 1,448 9,960 London 3,557 1,837 Wet herby 2,645 686 Overall1 16,103 (77 per cent.) 33,025 (80 per cent.) 1 Percentage figures relate to the total number of cases submitted in the stated period for 'evidential' or 'intelligence' casework.
§ Ms Blears
Retention periods depend on the purpose for which the sample was taken, and are as followsCrime scene samples on unsolved cases may be kept indefinitely, especially for the more serious cases. For crime scene samples on solved cases the usual retention period is seven years, but it may be up to 30 years for the serious cases in the event of a possible miscarriage of justice and to capitalise on new scientific developments.1502WFollowing amendment of Police and Criminal Evidence Act 1984 by the Criminal Justice and Police Act 2001 samples of suspects can now be held indefinitely.Where individuals have volunteered to provide samples for intelligence purposes these may also be retained indefinitely provided the individual has given their written consent for its retention.
§ Ms Blears
The laboratories that analyse DNA samples, including those within the Forensic Science Service, are also responsible for their retention, integrity, security and, where appropriate, their destruction. The conditions under which these laboratories store such samples must fulfil the requirements of the International Quality Standard ISO 17025 and the Data Protection Act 1998.
In addition, it is a specific requirement of the Custodian of the National DNA Database that DNA samples taken for entry on to the Database are kept in a managed storage system at a temperature below -150C in access-controlled, physically secure accommodation. Laboratories are required to undertake periodic monitoring of the samples and their compliance with the International Quality Standard ISO 17025 is independently audited at least annually by the United Kingdom Accreditation Service.