[theregister.co.uk] Special Report The National DNA
Database (NDNAD) keeps growing: it now holds more than five million DNA
profiles of individuals. Getting off the database, if you have been
sampled by England or Wales forces, remain as unlikely as ever. And it
remains difficult to make sense of the stats bandied at us, with the
press quoting wildly differing figures. So we decided to investigate.
In August, the Daily Mail reported that "4.5 million genetic profiles [are] on record. Up to 1.5 million – or a third of these – are from innocent people".
In another article on the same day, the Mail
reported "[t]he figure of 573,639 people on the database who have not
been convicted, cautioned, formally warned or reprimanded has pushed
the overall total to 4.2 million."
This is an extreme example of the difficulty of making sense of
statistics concerning the NDNAD. Our first step was to find source data.
In May 2007 the National Policing Improvement Agency (NPIA) started to administer the NDNAD. We’ll use data obtained in a recent response
to a Freedom of Information request to the NPIA to get some sense out
of the data and figure out what are all the implied assumptions.
Data from the NPIA is authoritative, but the organisation’s view of
what is the NDNAD is a matter of opinion. The NPIA claims that "The
NDNAD is not a criminal records database. It holds very little
information about a subject’s identity – only their name, date of
birth, sex and ethnic appearance. Inclusion on the DNA database does
not signify a criminal record, and there is no personal cost or
disadvantage by being on it".
The National DNA Database Ethics Group and the Human Genetics Commission both consider the NDNAD to be a crime-related intelligence database. Recent findings suggest
that composite statistics do not mask identity within genome-wide
association studies and that DNA profiles previously considered
anonymous and not containing genetic markers may reveal much more than
was thought.
Often assumptions are made about the data; and these may not be the
same for different sets of data. The NDNAD includes profiles of DNA
samples taken by forces from England, Wales, Scotland and Northern
Ireland, but often figures given in Parliament or in the press are only
for samples taken by the England and Wales forces.
The NDNAD includes DNA profiles of the DNA samples taken from
individuals and profiles of the DNA found at crime scenes. Here are
figures up-to 2008-09-01.
| (At 2008-09-01) | England & Wales forces | Other forces |
| Total number of subject profiles | 4,969,225 | 327,088 |
| Estimated total number of individuals | 4,319,807 | 273,358 |
| Total number of crime scene profiles | 320,335 | 13,749 |
The subject profiles consist of both profiles of DNA samples taken
from individuals following arrest for a recordable offence, known as criminal justice samples,
and profiles of subjects who volunteered a DNA sample (whether those
that do so are sufficiently informed before they give their consent is
an issue that was raised during the presentation
of the Nuffield Council on Bioethics; the NDNAD Ethics Group has been
discussing the volunteer consent form for DNA sampling and accompanying
information), for example, for elimination purpose.
Another source of confusion is that the number of subject profiles
on the NDNAD is higher than the estimated number of individuals on it.
This is often misrepresented. It happens because some of the profiles
held are replicates. Multiple samples are taken from the same subject
and profiled when on different occasions there’s confusion concerning
the person’s name. Replication also happens when the police decide to
resample an individual. The number of replications is estimated at
around 13 per cent (it varies over time and between police forces).
Define innocent
A common question is how many of these individuals are innocents. This is particularly difficult to find out.
First, the National DNA Database was allegedly never set up to
record this information; this is in the Police National Computer (PNC).
Second, what is meant by innocent is not always consistent; the
obvious definition of all those never charged and those acquitted may
not map directly to the information available. The NPIA ran a report on
2008-03-31:
| (At 2008-03-31 for England & Wales forces) | Total individuals | Percentage of total |
| With a conviction, caution, formal warning or reprimand | 3,259,347 | 79% |
| No conviction, caution, formal warning or reprimand listed | 573,639 | 14% |
| Not known as PNC record removed | 283,727 | 7% |
| Estimated total number of individuals | 4,116,713 | 100% |
From the above table it can be deduced that, as of March 2008, there
were DNA profiles for at least 573,639 innocent individuals and
possibly for as many as 857,366 innocents. Fourteen to 21 per cent of
the sampled individuals recorded in the NDNAD are innocent.
Furthermore, that does not take into account any mistakes in the PNC.
What happens to the DNA samples and profiles of all those innocents?
Most of them are kept and retained forever. The procedure to get off
the NDNAD is complex and assume that one case is considered exceptional
enough to justify such a procedure in the first place.
See El Reg’s How to delete your DNA profile for more on this. (Note that the only process map the Metropolitan Police has published since is a rehash
of the usual guidelines and the Specialist Crime Directorate 12 wrote
that ‚[t]here is no additional information I can supply on this
subject‘.)
| Subject profiles removals | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 (adjusted) |
| England & Wales forces | 677 | 34 | 81 | 271 | 310 | 222 |
| Other forces | 23,492 | 19,160 | 21,580 | 21,969 | 21,265 | 19,164 |
The huge difference in numbers between removals of samples taken
England & Wales forces and by other forces is due to differences
between English & Welsh and Scottish laws. DNA profiles and samples
of innocents taken by Scotland forces can’t be kept forever.
Whether England and Wales forces can keep stalling on the removal of
DNA profiles (and destruction of DNA samples) of innocents has gone all
the way to the Grand Chamber of the European Court of Human Rights:
"The [Marper and S v. UK] case concerns the decision to continue
storing fingerprints and DNA samples taken from the applicants after
unsuccessful criminal proceedings against them were closed." The hearing
was in February and the ruling will be given later this year. (Note
that the adjusted figure for 2008 is based on data up to September
adjusted for the rest of the year.)
I did not request the data for calendar additions to the NDNAD, but
to put things in perspective, the yearly average number of subject
profiles added to the NDNAD for the the financial years 2005-07 was
711,645 (NPIA NDNAD Annual report data). For England and Wales forces it was 646,767 (John Reid in Parliament written answers).
Profiling at a young age
There’s particular concern as to how many young individuals are
included in the NDNAD. Depending on whether you consider the NDNAD as a
criminal database, being included in it at a young age is worrying.
| (At 2008-09-01) | England & Wales forces | Other forces |
| Total subject profiles from 10-17 year old | 343,745 | 10,671 |
The England & Wales forces again lead in in their aggressiveness
to sample DNA. Six pe rcent of all the profiles in the NDNAD were taken
by other forces, but only three percent of the DNA profiles of subjects
10 to 17 years old (when the report was ran) was for samples taken by
other forces.
The NPIA last ran a more complete report concerning 10-17 year-olds on 2008-04-10:
| (At 2008-04-10 for England & Wales forces) | Total individuals | Percentage of total |
| With a conviction, caution, formal warning or reprimand | 264,297 | 87% |
| No conviction, caution, formal warning or reprimand listed | 39,095 | 13% |
| Estimated total number of individuals | 303,393 | 100% |
(The number of those with a PNC record is one less that the
estimated total number of individuals. The NPIA did not state if
there’s one youngster with a PNC record already removed, which is
unlikely or whether this should be viewed as a statistical error). From
the above table, it can be seen that at least 39,095 innocent
youngsters are affected.
If you happen to live in England or Wales, being young or innocent,
or both, is not enough to ensure you won’t be captured in this massive
database. ®
Bootnote
It can be argued that retaining DNA profiles of individuals is not
even effective in solving crimes. Helen Wallace, from GeneWatch,
debunked this assumption last year when looking at who should be on the NDNAD:
"Collecting more DNA from crime scenes has made a big difference to
the number of crimes solved, but keeping DNA from more and more people
who have been arrested – many of whom are innocent – has not. Since
April 2003, about 1.5 million extra people have been added to the
Database, but the chances of detecting a crime using DNA has remained
constant, at about 0.36%."
David Mery is a technologist and writer based in London. Last
year he succeeded in having his DNA profile purged. His website is gizmonaut.net.
Source: http://www.theregister.co.uk/2008/11/06/dna_database_special/
