The National DNA Database - Home Affairs Committee Contents


1  Introduction


Background to our inquiry

1. Aware of growing public concern about the increasing size of the police National DNA Database, that certain ethnic and age groups were over-represented on it and that it contained information relating to people never charged or convicted of a crime, we decided that we would take evidence on this subject early in 2010. Our preparations for these sessions were overtaken by the Government's introduction of its Crime and Security Bill on 19 November 2009, which, amongst other things, proposed changes to the system for retaining DNA samples and profiles. At the time of writing, this Bill has completed its Committee stage and is about to come back to the House of Commons for the Report stage.

2. Although the evidence we received from our witnesses is already available to Members, the uncorrected transcripts having been published on the Committee's website, we consider it useful to the House to make a brief Report of our main conclusions. We have therefore decided to focus on two main issues in this Report: the principle of retaining DNA profiles taken from individuals arrested but not subsequently charged or from those charged but not convicted; and the lack of consistency in decisions to remove from the database their profiles on request from those individuals.

3. We would like to thank those who gave oral evidence to the Committee: Isabella Sankey of Liberty, and Ms Diane Abbott MP, who have campaigned on behalf of those wishing to have their DNA profiles removed from the database; Mr Jonathan Leighton and Mr Greg Hands MP, who have had their DNA profiles put on the database and who have had to apply for them to be removed; Chief Constable Chris Sims of the West Midlands Police, the ACPO (Association of Chief Constables) lead on forensics, and Mr Gary Pugh, Director of Forensic Services of the Metropolitan Police and Chair of the National ACPO DNA Strategy Board; Professor Sir Alec Jeffreys, who invented the techniques for DNA 'fingerprinting'; and Mr Alan Campbell MP, Parliamentary under-Secretary of State responsible for crime reduction, Home Office. We also received written evidence, which we have published with this Report, from GeneWatch UK, the Nuffield Council on Bioethics, the Equality and Human Rights Commission and from several individuals recounting their experience of having their DNA profiles stored. We have also made use of the oral evidence given to the Public Bill Committee on the Crime and Security Bill in writing this Report.[1]

Scope of the Report

4. Because of the complexity of the subject, there is frequent confusion over what exactly is being discussed in relation to removing records from the National DNA database. Two types of DNA sample are entered on the National DNA Database:

  • samples discovered at crime scenes, which may be those of the victim, an innocent person who had at some time been present at the scene of crime, or the perpetrator; these are stored in the hope that they may help to rule out the innocent from inquiries or be linked to a suspect;
  • samples taken from a named individual, which can be described as 'personal' samples. At present, the police collect DNA samples from everyone arrested.

DNA degrades over time. For this and other reasons, what is entered on the database is a profile, a series of numbers representing ten areas of DNA that are known to differ widely between individuals, plus an indication of the gender of the person profiled.[2] The database contains crime scene profiles and 'subject profiles' which have been derived from the personal samples. There is currently no time limit for the storage of DNA samples: the Crime and Security Bill would require the destruction of DNA samples[3] once they have been loaded satisfactorily onto the national database and, in any event, within six months of their being taken.[4]

5. It is important that the use of DNA in solving crime should be viewed in context. Chief Constable Sims told us that approximately 4.9 million crimes are reported each year, of which about 1.3 million are 'detected' (in other words, a suspect has been charged), and of these detected crimes about 33,000 involve DNA matching—which compares with about 45,000 detected crimes in which fingerprint evidence has played a part.[5] GeneWatch suggested to us that the figure of 33,000 represented both direct detections (detections in which a DNA match was directly involved) and indirect detections (where a link of a personal profile to one crime scene may, for example, result in the suspect confessing to a number of crimes: indirect detections are a relatively common feature in relation to burglary). Some 17,643 direct detections were recorded in 2008/09.[6]

6. It is worth noting two further points. No figures are available for the number of crimes where DNA matches have been found in which convictions have been obtained: the 33,000 figure relates only to charges brought, though the Home Office estimated in 2006 that around 50% of detections led to convictions.[7] The second point is that the figures given by Mr Sims do not show the breakdown between different ways in which DNA may be matched: cases where a person's DNA is found to match crime scene DNA already on the database (in other words, someone is arrested and their DNA is found to match the DNA either from the scene of the crime for which they were arrested or from another scene of crime to which they had not previously been linked) and cases where a later crime is linked to a personal profile already on the database. Only the second of these types of matches would be affected if a database of personal profiles did not exist. Again, no research has been carried out on how many matches are of the second type. GeneWatch has used a variety of official reports to achieve an approximation to such research: combined, they lead to the figure of 3,666 out of the 1.3 million detected crimes being detected at least in part because crime scene DNA has been linked to a personal profile already on the database.[8] It is currently impossible to say with certainty how many crimes are detected, let alone how many result in convictions, due at least in part to the matching of crime scene DNA to a personal profile already on the database, but it appears that it may be as little as 0.3%—and we note that the reason for retaining personal profiles on a database is so that the person can be linked to crimes he/she commits later.

7. For the first few years when personal DNA was systematically collected by the police, this was done when a person was charged with an offence. From April 2004, the police were permitted to collect DNA on arrest rather than charge.[9] While the number of stored personal profiles has increased dramatically—from 3.1 million in 2004/05 to over 5.5 million in 2008/09—and the number of recorded crimes has declined from its peak in 2003/04, the percentage of recorded crimes detected involving a DNA match has remained roughly stable, fluctuating between 0.63 and 0.76%.[10] In other words, the presence of more profiles on the database has not increased the percentage of crimes cleared up, even despite the fact that the number of recorded crimes has been decreasing.

8. Meanwhile, a policy decision in 2001 to collect more DNA from the scenes of volume crimes, such as burglary and theft, led to a sharp increase in the overall number of crime scene DNA profiles and, according to a Home Office report in 2005, "the number of matches obtained from the Database (and the likelihood of identifying the person who committed the crime) is 'driven' primarily by the number of crime scene profiles loaded into the Database" [Home Office's emphasis].[11]

9. It is not surprising that DNA is involved in solving only a small proportion of overall crimes, since both the 4.9 million and the 1.3 million figures include all types of crime. As Chief Constable Sims explained, most crimes do not have a 'scene' as such: they are relatively minor, and they are solved because the victim and perpetrator know each other, the police happen upon the incident as it is taking place, or by other normal policing means.[12] Even where the discovery of DNA is a possible and desirable—for example, in relation to serious violent crime or burglary—samples at crime scenes may be so partial or compromised by the presence of many people's DNA that they are unusable. By illustration, in 2008/09 there was a crime scene investigation in respect of 796,780 crimes, and 49,572 crime scene profiles were added to the database. Even if only one profile was added per crime scene (and often crime scenes yield a number of profiles), then DNA profiles were obtained for under 1% of recorded crimes.[13]

10. However, despite all this, DNA profiling remains an important tool for the police. As Chief Constable Sims said:

    In general, the more serious the offence, the bigger the part that forensic science plays in its detection and particularly the less contact there is between victim and offender, the more important forensic science becomes.[14]

For example, in 40% of the cases where DNA can be collected from the scene of a burglary, it plays a part in identifying a suspect.[15]

11. We wish to make it clear at the outset that we are strongly of the belief that DNA profiling and matching are vital tools in the fight against crime; and that it is essential, wherever possible, to gather, profile and store information relating to DNA discovered at crime scenes. Although it is very unlikely that DNA on its own could bring about a conviction for a crime—and, indeed, we understand that the Crown Prosecution Service requires further corroborative evidence before it will bring a prosecution—as Sir Hugh Orde, the head of ACPO, told the Public Bill Committee, DNA evidence places a person at the scene of the crime and he/she then has to explain why they were there or prove that the DNA match is faulty.[16]

12. Nor do we question the taking of DNA samples from everyone arrested for a recordable offence. We note that the identification of perpetrators of some very serious crimes, including murder, has been made possible by the matching of a personal sample taken in connection with a later, less serious offence with a crime scene sample.[17] We also support the principle, as set down in the Crime and Security Bill, of destroying the actual personal samples as soon as practicable, not least as they could theoretically be used to derive other personal information about the individual such as family relationships or information about health. In this Report we are solely concerned with the retention of personal profiles on the database: whose profiles should be retained, for how long they should be stored, and the processes for getting one's profile deleted from the database.


1  This is the House of Commons Committee that considered amendments to the Bill. An official report of its debates is published and available via the Parliamentary website at www.parliament.uk/Bills Back

2   See National DNA Database Annual Report 2007-09, p7 for a description of how a profile is derived. Back

3   Dental and footwear impressions and fingerprints are also covered by the Bill but are not the subject of this report. Back

4   See New Section 64ZA to the Police and Criminal Evidence Act as set out in clause 14 of the Crime and Security Bill. Back

5   Qq 38-41 Back

6   Ev 30  Back

7   Home Office (2006) DNA Expansion programme 2000-2005: reporting achievement, cited in GeneWatch's written evidence: Ev 30 Back

8   Ev 30-Ev 32 Back

9   Under the Criminal Justice Act 2003 Back

10   Ev 32, Table 1 (GeneWatch) Back

11   Home Office, DNA Expansion programme 2000-2005: Reporting achievement, (October 2005), para 32: to be found at www.homeoffice.gov.uk/documents/DNAExpansion.html Back

12   Q 44 Back

13   Number of crime scene investigations and number of crime scene profiles added to database from National DNA Database Annual Report 2007-09, respectively p27 and page 22, Figure 12. For number of recorded crimes, see paragraph 5 above. Back

14   Q 58 Back

15   Qq 70-71 and Ev 35 (GeneWatch UK) Back

16   Crime and Security Bill: Public Bill Committee, Tuesday 26 January 2010 (afternoon), Q 77  Back

17   One example of this is the conviction in 2008 of the murderer of Sally Anne Bowman: see the very clear account given by the Forensic Science Service at www.forensic.gov.uk/html/media/case-studies Back


 
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