Gov advisers slate Home Office over innocents' DNA retention
Arrests made just to collar DNA
The Human Genetics Commission has slammed the government over the rampant expansion of the UK's DNA database.
One retired police officer told the Commission that the databases existence had changed policing practices, with some officers making arrests purely to get samples on the system.
The Human Genetics Commission (HGC) is the Government’s group of independent advisers on developments in human genetics: it is hoped that its "nuanced" critique of government policy will avoid a repetition of the Nutt affair and the Home Secretary will not, on this occasion, go so far as to sack his experts for providing advice that is out of step with his own views.
The HGC report, Nothing to hide, nothing to fear, concludes that although Britain has the largest police DNA database in the world – five million strong and still growing – this has been developed piecemeal without a specific Act of Parliament. The database needs to be regulated on a clear statutory basis and supervised by an independent authority.
HGC Chair Professor Jonathan Montgomery said: "DNA evidence plays a significant role in bringing criminals before the courts and securing convictions. But it is not clear how far holding DNA profiles on a central database improves police investigations.
"We have to strike a proper balance between identifying offenders and protecting privacy, including that of innocent people – we should not compromise that privacy without good reason."
On retired police officer told the researchers that in contrast to practices in his early career, it was now "the norm" to arrest people for "everything there is a power to do so" in part to expand the database.
"It is apparently understood by serving police officers that one of the reasons, if not the reason, for the change in practice is so that the DNA of the offender can be obtained: samples can be obtained after arrest but not if there is a report for summons. It matters not, of course, whether the arrest leads to no action, a caution or a charge, because the DNA is kept on the database anyway,” the ex-copper said.
The report further concludes that:
- There is insufficient evidence at present to be able to say what use it is to hold DNA profiles from different people
- There needs to be very careful consideration of the equality impact of the database and any proposed changes to it
- There needs to be a clear and independent appeals procedure for unconvicted people who want their DNA removed
- All police officers should have their own DNA collected as a condition of employment
- The UK needs to make progress in working with the rest of Europe on exchanging DNA information and standardising procedures.
Government difficulties began last December, when the European Court of Human Rights ruled, in the case of Marper and S, that it was illegal to retain DNA profiles and fingerprints belonging to two men never convicted of any crime.
the same old same old in respect of the statistics of DNA matching.
There are two "sources of error" in dealing with DNA matches. The first is error due to a random match - and this is both what prosecution like to bleat about and what everyone else on this thread is going on about.
It is the probability that for a given number of DNA points sampled, some other individual on the planet will have identical DNA to your own. Various posters have correctly noted that this figure is usually in the millions to one against.
The second source of error is, quite simply, the probability of a false positive from ALL causal sources. False positives may arise because some bugger contaminated a sample. Because someone lied. Because samples got mis-labelled. And so on.
Such cases exist - and since court cases tend to run into the thousands worldwide...as opposed to the millions in each year.... an error for one of these reasons would occur with odds against of thousands to one. Not millions to one.
Oddly, outside of some very rarefied criminology departments, no-one much is researching this topic...which is a shame, because it would be pretty easy to get a lower limit figure for this sort of error.
And it would be disingenuous of courts to claim that one can talk about error due to random matches and not talk about error due to, well, error.
Basically, the chances of your getting a false positive on a DNA match are the chance of a random match PLUS the chance of a match by error.
Oh...and don't even get me started on the probability of having committed a crime given the presence of your DNA at the scene of crime. For rape, say, presence of genetically matching semen, if you are not claiming a misunderstanding over consent, is pretty damning evidence.
However, I have spoken to people "fingered" in cases where multiple DNA profiles were preent at the soc...and the police appear simply to have fancied them for the offence.
Stop being the paramilitary wing of the Office of National Statistics, and go and catch some real criminals.
Somewhere preferably not too hot. :P