DNA database reports shows costs up, 'detections' down

Researchers looking to assess the effectiveness of DNA profiling in solving crime are unlikely to take much comfort in the recently released Annual Report of the National Policing Improvements Agency (NPIA). Meanwhile, civil liberties campaigners must wait to discover what the Government plans to do about removing the profiles …

[Anonymous Coward]

DNA profiling

The immigration use of DNA profiling shows that it is inevitable that the Home Secretary will at some point profile DNA samples for propensity to crimes.

i.e. have X marker, means you'll be investigated for Y crime, because of a correlation between the two.

As you saw with Jacqui Smith's inability to distinguish between a causal relationship and a correlation, so DNA profiling is a correlation not a cause.

IMHO, the privacy right says there has to be a compelling reason to violate someone's privacy and that has to be balanced with the use.

When politicians have to pad the argument to keep innocent peoples DNA on file, it is a confession that they know the case isn't there to do it, and they just want to do it anyway.

It's a confession.

If there was a strong argument for keeping innocent people's DNA, then they'd make the argument and take everyones DNA. However the argument runs.... what harm can it do.... and on that basis try to take everyones DNA by stealth.

What harm can it do? My answer to that is two words: Jacqui Smith.

[James 47]

'Replicates'

DNA is supposed to be unique, how can there be replicates? Is it possible to hash a DNA sequence? Why do physical samples have to be stored?

[Pat 11]

around 13 per cent of the database consisting of "replicates".

It wasn't me, it was my clone.

But really, what is a replicate? Is it the same DNA with 2 different ID's?

[mark 63]

hell yeah

F**Kin A they should retain the profiles of innocent individuals!

what if they commit a crime later?

They should take samples at birth.

where the harm?

[mmiied]

13% repiclaers

but I thought they keep telling us that our DNA is unique and that is how it can bu used to help solve crime how come they have 13% dupiclates?

[Anonymous Coward]

@James 47

DNA *is* unique. However to sequence an entire genome would costs millions (why do you think it was such big news when the human genome was finally sequenced in it's entirety ?).

What is stored is *already* a hash, and so it's quite probable the more samples you add, the more "replicates" you will get.

Imagine trying to record the entire UK population by looking at Surname, Housenumber and Postcode Area ... you'll have loads of Smith-1-B32

[John Ozimek]

Replicates

Records are held at DNA sample level and not de-duped to individual. So, if two samples are taken from the same person, there will be two identical DNA records on file.

No issue with the DNA itseldf.

[Anonymous Coward]

Re: 13% "replicates"

Suppose you've got a profile for a Jack Smith with an address in Birmingham, and a profile for a Jake Smith in Manchester, and the DNA is the same. Then it's probably the same person, but you don't know which if either of the names and addresses is correct, and you can't rule out the possibility of identical twins, so you can't merge the records without further, expensive research. Seeing as neither DNA profile is linked to any current investigation, you just leave it as it is. What else could you do?

[Anonymous Coward]

Replication

Is usually down to the fact that a lot of criminals lie about their names (odd that, isn't it, that they'd lie about who they are), and they get arrested in different force areas as well,so the only thing that identifies Fred Blogs from Manchester as Joe Smith from London is the fact that when Fred's DNA profile is loaded on the DB it matches against Joe's which is already there.

Or that is how it used to be when I was involved in it.

[ElReg!comments!Pierre]

Just use encryption folks...

I'm on my way out already

[Anonymous Coward]

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waterboarding all nighter...

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thank you for your co-operation, we look forward to your return visit, have a nice day.

comeback soon y'all.

definitely an experience of a lifetime, never to be forgotten.

and all because you share the same "GCTAGGTTAACCT" string in your DNA that some Muppet who got blown up in a foreign country in a terrorist attack had!

hmmm looks like its definetly time to start hacking our own DNA to get off the database....

[Graham Marsden]

A "detection" ...

... "means that the crime was cleared up and a DNA match was available. It does not mean a conviction was obtained, or that guilt was established."

Why does this remind me so much of the vaunted "success" of the Patriot Missiles in Gulf War 1 where a "successful interception" meant that the Patriot simply *crossed the path* of an incoming Scud missile, not that it actually shot the damn thing down...

I also have to wonder with the DNA "detections" whether someone had already copped to the crime and *then* their DNA was taken and (lo and behold!) a match was found with an *existing* record!

[Richard 12]

@James47

The DNA 'fingerprint' is actually incredibly vague.

The physical process is essentially as follows:

1) Take a very big book, with each chapter printed on a single line on very long piece of paper.

2) Cut it into small pieces using certain rules: eg Cut after every incidence of the phrase "and the" or "fox"

3) You now have a pile of smaller pieces of various different lengths.

4) Now count how many pieces you have that are 1-100, 101-200, 201-300 etc letters long.

5) For a more accurate reading, you can have each piece that includes "and the" glow one colour, with each piece that includes "fox" glow a different colour.

Remember that you don't have any way of actually reading the text - you can only see what colour the pieces glow and roughly how long they are.

That is your "Book Fingerprint".

Now, your challenge is to convince people that you can tell the difference between any two books using this technique.

[M Room]

Cost Effective

Once a DNA sample has been taken and tested (at great expense to us the taxpayer), it is totally stupid to throw the results away and not store them for future comparison/detection/elimination.

If just one rapist or murderer is brought to book by the national DNA database then it is worth keeping the records. Let us not make life too easy for those that break the law with seeming impunity. Let us not slip back into the days of criminals being able to escape when we have tools to aid detection and then fail to use them.

This is not a matter of privacy but a matter of public order and safety for the innocent.

[Anonymous Coward]

Burglaries down, mugging up

I can't find the link, but there was an Economist article that put the fall in burglaries down to falling prices of TVs/DVD players etc, while smart phones, iPods etc meant that mugging was more profitable.

Falls in car crime are linked to improved anti-theft devices built in by the manufacturers.

[Anonymous Coward]

The basic error

Few articles on this subject ever mention the relevance of 'the birthday theorum.' (http://en.wikipedia.org/wiki/Birthday_problem)

As others have explained, a DNA profile is a summary of the person's genome. Very like an MD5 checksum. If you have a sample at a crime site and an existing suspect it's very unlikely than you'll get a false match. You can and should take a fresh sample from the suspect at that point.

OTOH, if you have samples from very many crimes and a large database of 'suspects,' things are different. The only reason for having the db is to ask 'who in this set matches any of that set?' Then the probability of a false match increases exponentially. It will very quickly fail the 'beyond reasonable doubt' test if you could only get jurors to understand that.

Or politicians for that matter...

[John Ozimek]

Matching

One issue...that perhaps not all readers have grasped...is that there is a difference between the odds on a random match, which is usually what gets quoted, and a false match.

The random odds are what are usually quoted These are the odds that the profile matches a particular unique individual and not some other individual, whose details may not even be on the database. Usually, these are in the realms of millions to one against, and reflect the fact that it is unlikely, barring twins, for one individual to have an exact genetic doppelganger elsewhere at large in the world.

What has not been properly studied are the odds on false mtches, which are matches that take place whenever the wrong individual's DNA gets matched for any reason - including procedural error, contamination of samples, etc., etc.

Some academics estimate the odds on false matches as considerably higher.