When is a murder not committed by a murderer?
You may remember that back at the end of February I posted about a couple of cases up for review by the European Court of Human Rights; at issue is the question of whether it is lawful (and adequately respectful of human rights - including proportionality) for the DNA of people arrested but subsequently found innocent or not charged to be added permanently to the UK's national DNA database.
Two things prompt me to revisit this story. One is recent news that Sir Simon Milton, Head of the Local Government Association, has written to local authorities to draw attention to disporportionate use of powers granted under RIPA, the Regulation of Investigatory Powers Act. Some councils have admitted "routinely" using RIPA to justify surveillance, including access to phone and email records, for offences including: owners allowing dogs to foul the pavement, clam-picking from an unclassified bed, and to spy on parents who claimed to live within the catchment area of a particular school (it was found that they did... but only after their children had been stalked for a couple of weeks. Never mind... that will all come out later, in therapy).
Incidentally, the Chief Exec of Wyre Council in Lancashire is quoted as saying, apparently without irony, that dog fouling is an issue which local people "want the council to be tackling on the ground". If they start trying to deal with it in mid-air I think we're all in trouble... and dealing with it any earlier than that really would be disproportionately intrusive.
More seriously, though, my second prompt was this story in The Register, concerning a speech made by Gordon Brown on June 17th 2008 at the Institute for Public Policy Research (IPPR). The speech - on the topic of Security and Liberty - covered, among other things, the justification for retention of records on the national DNA database (NDNAD). The Prime Minister said:
"I say to those who questioned the changes in the Criminal Justice and
Police Act 2001, which allowed DNA to be retained from all charged
suspects even if not found guilty: if we had not made this change,
8,000 suspects who have been matched with crime scenes since 2001 would
in all probability have got away, their DNA having been deleted from
the database. This includes 114 murders, 55 attempted murders, 116
rapes, 68 other sexual offences, 119 aggravated burglaries, and 127
drugs offences."
That seems entirely clear and unambiguous. Precise figures, relating to specific offences, cases and suspects. But strangely, I don't remember seeing the news headlines - "over 100 unsolved murder cases closed, thanks to DNA database matches". According to this analysis of Gordon Brown's speech, by Genewatch UK, that's because what the Prime Minister meant was actually something quite different.
The figures do not relate to specific cases or suspects.
They are based, first, on estimates of how many cases have been retained which might previously have been deleted from the database, before the law was changed to allow their retention; second, on estimates of how many of those retained samples might have matched samples from scenes of crime. It is not actually known, or reported in the NDNAD Annual Report on which the PM's figures are based, how many specific individuals' records have been retained, which might previously have been deleted. Nor do the figures say how many of those estimated matches ever resulted in a prosecution, let alone a conviction. Instead, Gordon Brown's precise-looking figures are, according to The Register's article, based on an estimate of how many of the (estimated) matching cases are statistically likely to have been murder cases, rapes, assaults and so on.
According to the agency responsible for running the NDNAD "it is not possible to provide figures for the number of convictions produced by DNA".
The Genewatch analysis is happy to go on with the statistical approach, though; according to their figures, for every 8 DNA matches on the database the police get about 4 detections (prosecuting an individual for an offence); about half of those result in a conviction, and half of the convictions result in a custodial sentence. That's... one.
I'm too thick to do it for 114 murders, but as a byte has 7 data bits plus one parity bit, I can do it for 112 murders: if that was 112 DNA matches, it would be 56 detections, 28 convictions and 14 custodial sentences.
Hmm. Where did the other 100 go? Ah - I remember... into the non-existent headlines. I can see it now:
"100 non-existent murderers not matched to anything in statistical estimates, says PM"