"Nothing to hide, nothing to fear?", HGC report alleges police abuse of DNA database

[Azrael]

The major problem with expanding the database to less serious crimes, let alone the innocent, is that there is a much lower prior probability of guilt, which means the probability of guilt after a DNA match is also much lower.

I imagine pragmatism is the reason why other countries are limiting their DNA databases to specific types of convict. Canada's supreme court has said the government is free to seize DNA from convicts, but so far as I know, Canada has stuck to it's designated offences criteria. Likewise, many US states restrict DNA seizure to certain types of felonies, although there's constant pressure to increase the scope of databases to misdemeanors, on the assumption that bigger is better.

The British government certainly thinks so, boasting about the size of our DNA database. I don't see it as a source of pride, but of shame, in both the hysterical authoritarianism that's swept the halls of power, and our inability to apply the most basic discernment without prodding from the Euro court.

 

[ymu]

A case I hadn't heard of before.

Sir—Adrian Linacre (May 31, p 1841)1
is an enthusiastic proponent of the
UK’s National DNA Database
(NDNAD). We wish to offer a more
critical perspective of the database.
In 2002, a young girl was murdered
in a Tuscan village by a foreigner.
From a bloodstain left at the crime
scene, the suspect’s DNA profile
was produced and circulated on the
Interpol net. In February, 2002,
T, a barman in England was
identified from the NDNAD and
charged with the murder. He denied
the charge and protested that he had
been at his workplace on the day of
the murder, which was corroborated
by several eye-witnesses. He was,
however, arrested. Eventually, British
officers reported a fresh profile from a
sample volunteered by Hankin, with
one previously unseen mismatch. He
was subsequently cleared of all
charges. This case highlights some of
the limitations of DNA profiling.
Inferring a person has committed a
crime on the basis of a profile match
alone is problematic. The rest of the
evidence should not be overlooked in
favour of the DNA match.
The use of DNA databases does
not prevent forensic scientists
from misrepresenting the population
associated with a crime (the forensic
population). A forensic population is
not an abstract category, but a small
group of individuals identified by
background evidence. In the past,
concerns have been raised about the
existence of genetic isolates and the
forensic use of gene frequency
multiplication rule. (2)
These hypotheses
have been strenuously and effectively
criticised.(3)
But informing a person’s
guilt probablility by comparison with
the national (or whatever other abstract)
population is a flawed approach that has
little to do with population genetics
axioms and their exceptions. Linacre’s
statementthat “such high probabilities
lead the investigator to place the person
at the crime scene” reiterates an
old cliché—technically known as the
fallacy of transposed conditional (4)
—here embodied in the desultory idea that
every man on earth can pass by a
Tuscan village on a certain day and
commit a crime.
Databases contain undetected
errors—the larger the database, the
more prone it is to errors.
THELANCET • Vol 362 • September 6, 2003; p834

Google gets 775 hits for hankin + tuscan + DNA + murder - the only relevant ones appear to be to the article I've quoted above. There's zero hits on google news. Makes no difference if you use Tuscany, or remove the term tuscan altogether. Did it ever hit the media? How many cases like this are there? Nobody knows.

 

[Azrael]

Are they not keeping such records now? Seems utterly irresponsible to me if so.

The whole thing is irresponsible to its core. And the worst thing? Until last year, Labour didn't start seizing the DNA of convicted rapists and murderers, because they'd been arrested before the database came online. So this government, that said it was so concerned about the risk to innocents that it had to seize DNA from 10-year-olds without a warrant and database it for life, allowed known rapists, murderers, and assorted other crooks to wander around unrecorded!

Labour don't give a damn about innocent people. If they did, they wouldn't trample over the privacy of presumptively innocent prisoners. All they care about is the power of the state.

 

[detective-boy]

Are you doubting the maths, d-b, or what? I don't see what your point is here.

I understand the argument.

But it is a prediction based on statistics ... and I am saying that if it actually were the case we should be seeing dozens and dozens of false matches ... and we are not (I know we are not as I have been privy to the actual results of matches and know there are not dozens of such false matches out there and I am arguing that that is confirmed by the fact that if they were there we'd be hearing about them as there is nothing at all to stop the victims of such false matches telling their story and nothing to stop the media running with it ... the eact opposite in fact, they'd be splashing it right left and centre as they do with anything related to our surveillance society.

I do not believe the worst case scenario used to come up with the "one false match every couple of hundred comparisons" figure.

As for keeping figures of the outcomes of matches, they probably are in there somewhere, just not collated and / or published in a coherent way. I believe the figures would confirm my view. I would have no problem with them being collated and published at all.

 

[detective-boy]

So a database with millions of samples isn't significantly slower, or harder, to search than one with a few thousand?

No.

What's your opinion on changing the law so the police can't seize DNA without a search warrant, issued only if the DNA is needed to investigate a specific crime, and after a judge has found reasonable grounds?

That would be a ridiculous and meaningless layer of bureaucracy.

DNA (and fingerprints) should be kept only for conviction cases where there is "proper" crime (our definition of "recordable" offences is ridiculously low for criminal records generally). They should only be taken on charge with such an offence (unless there is an investigative need for them in which case the authorisation of a Supt in PACE is sufficient in my opinion).

Putting the need for a warrant in would change nothing of that sort of system (any more than putting it in for the Insp. authorised s.18 PACE searches would have any meaningful impact). I could probably count on the fingers of one hand the number of times a Court would have refused a warrant and the cost would be delay and massive additional cost / bureaucracy in every case.

 

[detective-boy]

http://articles.latimes.com/2008/jul/20/local/me-dna20

If none of this applies to the British database, fair enough.

2001 is ancient history as far as DNA technology is concerned. The same arguments about no-one knowing how frequent profiles are applies equally to fingerprints (except that we've been doing fingerprints for donkeys years and haven't found an identical one yet) whereas (a) we've been doing DNA for far less time and (b) we are still only looking at a bit of the full DNA sequence (a bit like doing fingerprinting only using the top left bit of the third finger on the right hand ... in which case there may well be some matches out there.

 

[Azrael]

Putting the need for a warrant in would change nothing of that sort of system (any more than putting it in for the Insp. authorised s.18 PACE searches would have any meaningful impact). I could probably count on the fingers of one hand the number of times a Court would have refused a warrant and the cost would be delay and massive additional cost / bureaucracy in every case.

Bureaucracy is "administration characterized by excessive red tape and routine". Given that the police are, apparently, arresting people simply to seize their DNA, I don't think getting an independent party to authorise seizure of DNA is at all excessive. Since DNA is only used, by one reckoning, to solve 0.5% of crime, this won't be an issue in most cases. I've seen little complaint from Canadian police about the need to get a warrant, either to search houses, or seize DNA. The author of the Policeman's Blog (yes, him, sorry ) has commented on the Canadian system's flexibility and lack of bureaucracy since he transferred.

If biometrics are taken on charge, should they be entered onto a database, or should this only happen after a conviction?

Not sure about fingerprints, which are much, much less intrusive than DNA.

*edited to add* And a warrant's usefulness doesn't just lie in it being refused. Making the police go to the trouble of attending a court and testifying to a judge if they want to search a person or property is an excellent way to discourage frivolous or malicious searches, and usefully, allows corrupt officers to be prosecuted for perjury. Classic separation of powers, and nothing to do with bureaucracy.

 

[Azrael]

2001 is ancient history as far as DNA technology is concerned.

I know. The article dates from 2008, and says Ms Troyer began in 2001, subsequently finding "dozens of similar matches -- each seeming to defy impossible odds".

Fingerprints are of course unique. The discovery of DNA fingerprinting seemed to have given us an equally precise tool, with much greater scope. Fair to say it was a forensic scientist's dream come true. Perhaps we spoke too soon.

 

[ymu]

2001 is ancient history as far as DNA technology is concerned. The same arguments about no-one knowing how frequent profiles are applies equally to fingerprints (except that we've been doing fingerprints for donkeys years and haven't found an identical one yet) whereas (a) we've been doing DNA for far less time and (b) we are still only looking at a bit of the full DNA sequence (a bit like doing fingerprinting only using the top left bit of the third finger on the right hand ... in which case there may well be some matches out there.

Well, that's exactly the point isn't it? We have never found two matching fingerprints from different people, but we have found them from DNA samples. We know that in theory we should find them from DNA profiling, and we know that in fact we do find them from DNA profiling.

This does not appear to have been published yet (the abstract is dated May 2009) - I can't find it in anywhere, anyway (but then I haven't checked all the databases, there's hundreds of them). Unfortunately most of the relevant papers on this topic are in the Journal of Forensic Statistics, which I can't get online access to.

Trawling DNA Databases for Partial Matches: What is the FBI Afraid of?

David H. Kaye
The Pennsylvania State University Dickinson School of Law

Cornell Journal of Law and Public Policy, Forthcoming

Abstract:
DNA evidence often is presented as the “gold standard” for forensic science. But this was not always so. For years, eminent scientists complained that the estimates of the tiny frequencies of DNA types were unfounded. It took hundreds of research papers, dozens of judicial opinions, and two committees of the National Academy of Sciences to resolve the dispute by the mid-1990s. Since 2000, however, reports have surfaced of shocking numbers of “partial matches” among samples within large DNA databases, and some scientists have complained that the infinitesimal figures used in court to estimate the probability of a random match are no better than alchemy. To study the partial-match phenomenon further, defendants have sought to discover all the DNA records (with personal identifiers removed) kept in offender databases. The FBI has responded by branding the proposed research as useless and the release of the data as an illegal invasion of privacy. The media have reacted by calling for Congressional hearings and, possibly, criminal charges against FBI officials.

This article reviews the existing research findings and considers the scientific, legal, and ethical objections to disclosure of the DNA data. It concludes that the arguments against further research are unpersuasive. At the same time, it finds that the claims of dramatic departures from the expected numbers of partial matches are exaggerated and predicts that new research will not reveal unknown flaws in the procedure for estimating the chance of a match to an unrelated individual. In view of the importance of DNA evidence to the criminal justice system, the article recommends using the databases for more statistical research than has been undertaken so far. It also calls for dissemination of the anonymized records for this purpose.

http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1399658

The point is that we just haven't got enough research available to know the theoretical probabilities, or the frequency of human error, and the FBI have been blocking access to CODIS to check on some curious results. It is true that some of the excess numbers of matches found in even quite small databases (IIRC in a database of 60,000 offenders, they compared each profile to every other profile and found dozens of matches)* have been due to duplicate entries and familial relationships - but that's not much comfort, quite frankly.

I'm no longer interested in the theoretical probability of a false match - that was needed to establish these databases in the first place. Now that we have these databases, we can research the actual probability of a false match. But the UK government, with the biggest single database in the world, has not been keeping records, let alone doing proactive research, and the FBI is actively blocking research on CODIS, the second largest such database.

We do know that DNA evidence is less reliable than fingerprint evidence - we just don't know how much less reliable, because the research has not been done.


*E2A; I make that 1.8 billion comparisons - there should have been approx 2 chance matches according to the theoretical probabilities. We do that many comparisons every 360 samples run through NDNAD (1.8 billion/5 million).

 

[Azrael]

We do know that DNA evidence is less reliable than fingerprint evidence - we just don't know how much less reliable, because the research has not been done.

This is what's worrying me. If something's looks too good to be true, it usually is. Fingerprints are an exception, one that, perhaps, won't be repeated in other areas of forensic science. DNA has long been portrayed as nigh-on infallible, a miracle crime-fighting tool. I think it's healthy, and sensible, to be suspicious of this, especially as it's this attitude that's led Labour to an indiscriminate and fanatical mass seizure of biometrics.

Just look at how it's warped the attitude of senior police officers, who are abusing the power of arrest to grab as much DNA as possible. To say nothing of the abuse of due process, is this a sensible and proportionate use of resources? No. And behind it lies a nasty authoritarian assumption about the public, who are seen as potential murderers and rapists, to be cataloged whenever possible.

And then there's the inconsistency in this authoritarianism. What happens when we catch Mr Rapist or Mr Murderer? Why, we warehouse them for a few years, then release them back onto the streets. Labour's alleged concern for public safety is selective in the extreme.

 

[ymu]

From Azrael's link, better than my failing memory ...

Encouraged, Barlow subpoenaed a new search of the Arizona database. Among about 65,000 felons, there were 122 pairs that matched at nine of 13 loci. Twenty pairs matched at 10 loci. One matched at 11 and one at 12, though both later proved to belong to relatives.

65,000 entries compared to all 65,000 others is (65,000/2)*65,000 = 2,112,500,000comparisons made to yield that number of chance matches.

2,112,500,000/5,000,000 = 422.5

The forensic service uses 10 loci, when available (fewer when the sample is degraded). If Troyer's figures are correct, we'd get 20 false matches for every 423 samples run, or one for every 21 samples. If the theoretical probabilities are correct, we'd get one every 200 or so.

We need to know the actual probabilities, but even in the current best case scenario it's an unacceptably high risk. I don't want anecdote, I don't want theoretical probabilities - I want some research, dammit.

 

[ymu]

But hey, it used to be a helluva lot worse ...

1.4 With the introduction of the NDNAD, forensic science, as opposed to
police science (fingerprints) is, for the first time, able to provide direction to the
investigator. The current process of DNA profiling used in the UK examines 10
hypervariable regions of DNA (short tandem repeats or STRs loci) plus a
marker to determine gender. This process is termed SGM Plus®. The use of
short tandem repeats was introduced in 1994 when 4 loci were analysed, this
extended to 6 loci plus the gender test (SGM) and in 1999 the 10 locus test
(SGM Plus®) was introduced. These tests were all standardised for 28 cycle
amplification from originally 2 nanogram (ng) of DNA before the increase in
sensitivity in 1999 permitted 1ng of DNA as the standard starting template.

http://www.cps.gov.uk/legal/assets/uploads/files/review of low template dna analysis.pdf

 

[Azrael]

We need to know the actual probabilities, but even in the current best case scenario it's an unacceptably high risk. I don't want anecdote, I don't want theoretical probabilities - I want some research, dammit.

Hopefully the human genetics commission will get on it, although better yet if it's an independent body.

We don't need the HGC to tell us that current search and seizure policies are excessive and a violation of due process. Authorisation from a senior officers isn't much better. Seniority doesn't bestow independence, and given what the reports have been saying, they're as eager to grab DNA as anyone.

All this is linked to a wider debate about what arrest is actually for, although all our parties ignore this, if they're even aware of it. I take the traditional common law view that it's a means to ensure suspects arrive in court. PACE and other laws have imported the Continental view that it's a tool for investigation. This civil law philosophy leads to sweeping police powers. Time we deported it.

 

[littlebabyjesus]

PACE and other laws have imported the Continental view that it's a tool for investigation. This civil law philosophy leads to sweeping police powers. Time we deported it.

That's an interesting comparison. It certainly means that to be suspected is, in Foucault's words, already to be a little bit guilty.

 

[ymu]

A similar fight occurred in a death penalty case in Maryland during the summer and fall of 2006.

The prosecutor saw a DNA match between a baseball cap dropped at the crime scene and the suspect as so definitive that he didn't plan to tell the jury about the chance of a coincidental match, records show.

Seeking to cast doubt on the evidence, the defense persuaded the judge to order an "Arizona search" of the Maryland database. The state did not comply.

<legal wrangling, they were eventually forced to comply>

The search went ahead in January 2007. The system did not go down, nor was Maryland expelled from the national database system.

In a database of fewer than 30,000 profiles, 32 pairs matched at nine or more loci. Three of those pairs were "perfect" matches, identical at 13 out of 13 loci.

This is the issue. Juries are being routinely misled as to the strength of DNA evidence, and even when the statistical probabilities are appropriately presented in court, the theoretical calculations may be massively different from the truth.

We cannot know how many false convictions have been based on unreliable DNA evidence - we don't know who's innocent and who's guilty. We do not know how many people have been identified as suspects and eliminated or cleared at some stage prior to conviction, because those records are not being kept.

 

[Azrael]

That's an interesting comparison. It certainly means that to be suspected is, in Foucault's words, already to be a little bit guilty.

There's a fascinating book (annoyingly I can't remember the title, will try to sniff it out of Google) that compares police powers in Germany, France, England and Wales, and the USA. Basically, English law is becoming more Continental.

Until PACE, English police powers were very similar to American ones. The problem came in the fact they were regularly abused.

Civil law treats arrest as investigative detention. Continental police have long been able to search the homes and property of prisoners without a warrant, and enjoy lengthy interrogation time, usually without a lawyer present. (Watch Spiral/Engrenages to see the result. ) We've imported this with PACE, sweeping away the requirement for search warrants for prisoners, and allowing magistrates to extend detention to facilitate interrogation and investigation. Thankfully we allow lawyers to be present, mostly.

The common law treated arrest as a means to get suspects to court, and police had to get their prisoners before a magistrate as soon as possible. The police were allowed to investigate during any unavoidable delay, but it wasn't grounds for prolonging detention. Lord Denning quietly abolished this common law rule in 1965's Dallison v Caffrey, and introduced "investigative detention" on the quiet. Gene Hunt promptly emerged.

This is all fantastically obscure, but gets to the heart of the matter.

 

[littlebabyjesus]

It's positively medieval at heart – the justification for torture was that to be suspected meant a degree of guilt. Having your details taken and kept for ever simply for having once been suspected uses the same logic; even more so if the nature of the crime you were cleared of determines how long your details are kept – to have been found not guilty of rape, it appears, is a more serious offence than to have been found not guilty of burglary. It's a moral and logical mess.

It reminds me of a disgraceful (in other words typical) report on Today the other day about the 12 'suspected terrorists' who were held without charge for two weeks a while back. The police representative stated bluntly that there had been sufficient evidence to justify the arrests and the detentions, omitting to add 'but not enough evidence to charge anybody'. These poor buggers, who have already served two-week sentences, are still being spoken of by the authorities as if they were guilty of something.

 

[Azrael]

It's positively medieval at heart ...

To be fair to those medieval folks, they tended not to torture in regular common law cases, with the exception of crushing the prisoner under a pile of rocks if they refused to enter a plea.

– the justification for torture was that to be suspected meant a degree of guilt. Having your details taken and kept for ever simply for having once been suspected uses the same logic; even more so if the nature of the crime you were cleared of determines how long your details are kept – to have been found not guilty of rape, it appears, is a more serious offence than to have been found not guilty of burglary. It's a moral and logical mess.

Exactly. The seriousness of a crime has no bearing on the likelihood of guilt. Being acquitted of rape or murder implies no greater likelihood of guilt than being acquitted for piddling in the street. Yet this bizarre thinking has infiltrated even so-called defenders of liberty: the Lib Dems think murder suspects should continue to be subject to double jeopardy.

This thinking has also led to an absurd increase in police powers of detention. PACE said police had to charge or release within 24 hours, except for "serious arrestable offences", where the limit was upped to four days, with the nod from a JP. When Labour made all offences arrestable a few years back, this was changed to "indictable offences". So now the police have the power to hold your for four days without charge for nicking a CD!

By contrast, those wacky Canadians have decided that all prisoners, including suspected terrorists, must be charged or released within 24 hours. Their system isn't perfect -- they allow the police to interrogate suspects without a lawyer present -- but it's much closer to the common law tradition than ours has become. (Oddly so is Scotland's, which, despite being a civil/common law hybrid, allows only six hours of detention without charge, and gives the police no power to search homes or conduct intimate searches without a warrant.)

 

[Azrael]

It reminds me of a disgraceful (in other words typical) report on Today the other day about the 12 'suspected terrorists' who were held without charge for two weeks a while back. The police representative stated bluntly that there had been sufficient evidence to justify the arrests and the detentions, omitting to add 'but not enough evidence to charge anybody'. These poor buggers, who have already served two-week sentences, are still being spoken of by the authorities as if they were guilty of something.

Yes, I remember that fiasco, and posted about it at the time. If the police were obliged to charge or release within 24 hours (as they should be), they wouldn't have arrested with so little evidence.

It shouldn't be overlooked that authoritarian powers can also help the guilty. If those men were guilty as (not) charged, they benefitted from a law that allowed the police to jump the gun. If the case had to be much stronger before arrest, perhaps they'd be on remand now. We'll never know, I guess.

 

[littlebabyjesus]

We have a new 'legal' category – suspicion. And control orders can be issued indefinitely if you are guilty of being suspected. This is not law. It is a step down the road to totalitarianism. Yet, amazingly in the case of control orders, many people are completely unaware of what is happening.

 

[ymu]

It reminds me of a disgraceful (in other words typical) report on Today the other day about the 12 'suspected terrorists' who were held without charge for two weeks a while back. The police representative stated bluntly that there had been sufficient evidence to justify the arrests and the detentions, omitting to add 'but not enough evidence to charge anybody'. These poor buggers, who have already served two-week sentences, are still being spoken of by the authorities as if they were guilty of something.

There's thousands of people who've been arrested and released without charge in similar circumstances - often in high profile PR actions. Three friends of mine got caught up in the North London one 5 years ago - one released as soon as they realised he had indefinite leave to remain, the other two cleared of all suspicion, banged up in detention centres and deported back to Lebanon, which they had fled because their fathers were forcing them to fight for Hezbollah.

 

[Azrael]

Interestingly, an Australian court made a very similar comparison in the 1940s.

It appears, from recent cases that have come before this and other Courts of this State, that this rule of law with respect to arrests is being disregarded, and that arrested persons are being taken, not to a magistrate to be charged, but to a police station, where they are questioned by the police, sometimes for many hours, in the hope of extracting from them something that can be used in evidence against them ...

Indeed, there seems to be a growing impression in police circles that so long as a constable, after making an arrest, gives the usual caution, there are no limits to the extent to which he may go, short of violence, threats, promises, or lies, in endeavouring to extract admissions from his prisoner.

If these methods are tolerated, it is a short step to the moral, if not physical, tactics of the Gestapo and the Ogpu.

That comes from this report, the best history of common law police powers I've found online.

Control orders, which look likely to fall apart before long (although you can never be sure) aren't the worst of it. As few commentators have yet realised, there's no logical reason why people out on "police bail" (another PACE innovation) can't be remanded on the same grounds.

Our law's in a mess, and won't be put right until police powers are drastically reduced, and our unacknowledged third category of "suspect" confined to the dustbin of history.

 

[Azrael]

There's thousands of people who've been arrested and released without charge in similar circumstances - often in high profile PR actions. Three friends of mine got caught up in the North London one 5 years ago - one released as soon as they realised he had indefinite leave to remain, the other two cleared of all suspicion, banged up in detention centres and deported back to Lebanon, which they had fled because their fathers were forcing them to fight for Hezbollah.

I've also known people who were dragged off to immigration detention with zero justification, for the purpose, I strongly suspect, of intimidating them into dropping their asylum claim (they were subject to repeated threats of deportation, driven to the airport, and then told the flight had been cancelled). The birthplace of the common law should not be copying the behaviour of a two-bit banana republic.

Dictatorships love grey categories like "protective custody" and "immigration detention". Add "investigative detention" to the list, in my view. They're all rooted in the same doctrine, that the individual is an expendable creature rightly at the mercy of the state.

 

[ymu]

I've also known people who were dragged off to immigration detention with zero justification, for the purpose, I strongly suspect, of intimidating them into dropping their asylum claim (they were subject to repeated threats of deportation, driven to the airport, and then told the flight had been cancelled). The birthplace of the common law should not be copying the behaviour of a two-bit banana republic.

I agreed to stand bail for one of my friends (a mate offered to do the same for the other). At the first appearance in court the magistrate was clearly appalled at what had happened but couldn't grant immediate bail for some technical reason (they'd left some of his papers back at the detention centre, I think), and ordered a second appearance with the strong suggestion that bail would then be granted. They did not bring him to court for the second appearance. He was on a plane to Lebanon before a third date could be fixed.

 

[Azrael]

I agreed to stand bail for one of my friends (a friend helped the other). At the first appearance in court the magistrate was clearly appalled at what had happened but couldn't grant immediate bail for some technical reason, and ordered a second appearance with the strong suggestion that bail would then be granted. They did not bring him to court for the second appearance. He was on a plane to Lebanon before a third date could be fixed.

And at the behaviour of the authorities.

We also had the bail merry-go-round, with the two people in question detained for several weeks, released on a surety, and then re-arrested and deported. They were taken from their house by force, around 5am, and without a warrant. There was zero justification for a pre-dawn raid, and the courts were treated as an afterthought, at best.

Given that this is how the government behaves when it can get away with it, I have no interest in supporting anything but the most tightly controlled police powers.

 

[detective-boy]

Given that the police are, apparently, arresting people simply to seize their DNA

Before you base a wholesale change of the process on that, I think you need to get it into perspective. I am not surprised that there have been a few instances - in fact, that has been one of my criticisms of keeping the DNA of unconvicted persons since it started - but there have been no numbers on the reports I have seen. I have seen a couple of reports where the language used has suggested the numbers are very small. I have seen reports where it has been acknowledged that the arrests are not unlawful as such, just that discretion has been exercised in a way which leads to arrest (so as to get the DNA) as opposed to deal with an incident by way of a summons, fixed penalty notice or warning (which wouldn't).

Since DNA is only used, by one reckoning, to solve 0.5% of crime, this won't be an issue in most cases.

You entirely ignore that DNA is important in far, far more of the most serious cases ... largely because of cost - it could be used in solving lots of thefts from motor vehicles and burglaries ... but the cost can't be justified.

I've seen little complaint from Canadian police about the need to get a warrant, either to search houses, or seize DNA.

Which suggests that it actually doesn't provide any sort of barrier to getting the warrant as I suggested. It is simply a bureaucracy - it doesn't actually deliver any sort of safeguard ... in which case there is no point in having it.

If biometrics are taken on charge, should they be entered onto a database, or should this only happen after a conviction?

They should be searched against the database at that point. I personally have no particular view about whether they are actually put on the database then or at conviction. In view of charge being (effectively) based on "balance of probabilities" evidence on the face of the papers I could agree with it being then, in view of it not being an actual conviction I could agree with waiting. I don't think it would be a major issue one way or the other as the periods concerned would be relatively short. Bureaucracy-wise I would suggest waiting for conviction would make more sense rather than doing something and then having to undo it in some cases.

Not sure about fingerprints, which are much, much less intrusive than DNA.

What is it that you are concerned about? The intrusiveness of the process of getting the sample? (buccal swab v hands on a scanner) The intrusiveness of the sample itself? (my DNA is more personal to me than my fingerprints) Or the principle of your biometrics being kept on a database, effectively labelling you as a potential future criminal? (you are on the system, but I am not). Personally I see little sgnificant difference in the first two - that is not the issue for me at all. The latter is the biggie ... and that is why we must be able to defend the fairness and logic of it (which we cannot at present and won't be able to even with the governments proposed changes which still seem to assume that everyone who is arrested is at least involved to some extent in some criminal activity ... which they blatantly are not necessarily.).

Making the police go to the trouble of attending a court and testifying to a judge if they want to search a person or property is an excellent way to discourage frivolous or malicious searches, and usefully, allows corrupt officers to be prosecuted for perjury.

It is also an excellent way of giving idle / incompetent officers an additional excuse for failing to properly investigate incidents. The dataset doesn't exist, but having lived through the change to PACE, when we moved from needing to get a warrant to search someone's address, even after arrest, to being able to get a senior officer to approve such a search I would guarantee that dozens and dozens of serious criminals would not have been arrested (or not have been arrested so soon) before the change was made - we simply did not bother in most cases, even if we had loads and loads of grounds to go and wake a Magistrate up at 3am.

There need to be checks and balances ... and there are. I would have no problem with making them more accessible and effective (for instance, a specific criminal offence similar to malfeasance in public office but at a lower level of compelxity and seriousness for officers found to have deliberately breached the rules) and putting in place the power of any Court to directly commence criminal proceedings against an officer for that offence if they find that there has been malpractice during a prosecution case or civil action.

 

[Fruitloop]

A database with millions of records is most definitely harder to search, as I should know, as I write them for a living and I'm fixing one right at this moment.

 

[ymu]

Which suggests that it actually doesn't provide any sort of barrier to getting the warrant as I suggested. It is simply a bureaucracy - it doesn't actually deliver any sort of safeguard ... in which case there is no point in having it.

*edited to add* And a warrant's usefulness doesn't just lie in it being refused. Making the police go to the trouble of attending a court and testifying to a judge if they want to search a person or property is an excellent way to discourage frivolous or malicious searches, and usefully, allows corrupt officers to be prosecuted for perjury. Classic separation of powers, and nothing to do with bureaucracy.

Why are you saying that a warrant in the Canadian case is pointless bureaucracy, and then adding later on that a warrant acts as a deterrent against malicious or frivolous action? Why is it OK in one case, and not in another?

 

[detective-boy]

Well, that's exactly the point isn't it? We have never found two matching fingerprints from different people, but we have found them from DNA samples.

You are missing an important point and, as a result, comparing apples to oranges.

There have been lots of false positive and false negative fingerprint matches. The situation we have is not that there have never been any of them ... just that when they have been investigated they have been found to be based on a match between parts of a fingerprint or by the very slight differences being miscoded (the pattern of whorls and loops being converted into a digital entry by person (originally) or computer (now).

What we have never seen, so far as I am aware, is two identical full fingerprint sets when thoroughly examined at the minutest level of detail.

That is exactly the same with DNA. The DNA profiling technique is a method of taking a "snapshot" of the DNA sequence of the individual. Theoretically (and I very much suspect this will turn out to be absolutely true) none of us have exactly the same full DNA sequence. But we know that we share a huge amount of similarity (not only with each other but, decreasingly with other chimps, mammals, types of animal ...). Profiling, which is targetted on the areas of the sequence which are known to differ, is effectively like looking at partial fingerprints rather than a full set ... and it is absolutely no surprise to find that some of those results are matched.

But, just like the case with fingerprints, I have not heard of any case in which that match of the snapshot is not later found not to actually be a match when either examined in more detail or with more specific profiling techniques (there are many more techniques in development as science knows that, at present, it is only looking at a snapshot - the "gold standard" is the DNA sequence ... which theoretically will be absolutely unique but which is some way away.)

The problem is not with the technique - it is sufficient to differentiate clearly between individuals in the vast majority of cases. The problem is with understanding of the technique (by police, CPS, Courts) and of what it means. You wouldn't convict someone on the fact that they look like the CCTV image of the suspect alone (though we know that most of us look very different we also know that all of us look very similar to someone somewhere) though it may be (should be) grounds to investigate that individual further. We should treat DNA in that sort of vein.

 

[detective-boy]

DNA has long been portrayed as nigh-on infallible, a miracle crime-fighting tool.

Only by fuckwits (mostly in the media) who don't understand what it is (and isn't).