Memorandum submitted by the Home Office
When I gave evidence to the Committee on 5 January,
Tom Bake asked whether there were any studies of the cost-effectiveness
of the National DNA Database (NDNAD) as a tool to prevent and
detect crime. Having looked into this issue, we are not aware
of any independent cost/benefit analysis ever being commissioned
on the effectiveness of the NDNAD.
Information on the number of crimes that have
been detected using DNA profiles, whether or not they originated
from samples taken from suspects who had previously been arrested
but not charged with an offence, is not collected by the Home
Office. In any event, as Chief Constable Chris Sims said when
he gave evidence to you, detections are achieved through an integrated
criminal investigation process and not by forensic science alone.
However, some research information is available on the number
of DNA profiles that have resulted in a DNA match, providing the
police with, at the very least, an intelligence link on the possible
identity of the offender and assisting in the detection of crimes.
Since May 2001, 306,379 crime scene profiles
have been identified, linking crime scene and subject profiles
generated by the NDNAD. Fo 226,393 of these crime scene-to-subject
matches, a single subject was reported as being linked to the
crime scene(s) by their DNA. The identification of more than one
potential suspect can also occur, due to the crime scene profile
being only a partial profile or due to the number of replicate
subject profiles held on the Database.
A significant number of these cases are unlikely
ever to have been solved without the availability of DNA crime
scene evidence and a database against which to match the crime
scene sample. In other cases, many hours of labour intensive and
costly investigation work is likely to have been required to reach
the same end result.
So while there is no independent empirical evidence
as to the cost-effectiveness of a national database of DNA profiles,
it is apparent that the availability of such information is essential
in investigating some offences and gives a significant saving
in the investigation of many others.
January 2009
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