A database too far?

Home Secretary Jack Straw has announced plans to increase the police's DNA database. Civil liberties groups have serious misgivings about the proposal, which could have far-reaching consequences.

Jack Straw has announced plans to change the law to allow the police to keep all fingerprints and DNA samples even if a suspect is acquitted or never charged.

The proposal is included in the Criminal Justice and Police Bill, which was published on Friday.

At present fingerprints and DNA profiles - genetic fingerprints which can help prove a person's guilt - have to be destroyed if charges are dropped or a suspect acquitted.

The bill would allow them to be retained.

Written consent

It also allows for DNA samples procured for reasons of elimination - for example when men living in the locality of a rape or murder volunteer their DNA in order to help police narrow down their list of suspects - to be retained.

But in this case, the donors have to give their written consent for police to keep their samples, otherwise they will be destroyed.

Both changes should increase the number of samples in the police's database from 940,000 to about three million in the next three years.

The DNA database at the Forensic Science Service laboratory

These could then be matched with DNA evidence left at new crime scenes.

All that is needed to extract DNA is one cell - a speck of blood, a swab of saliva or a miniscule fragment of skin that clings to a strand of hair.

DNA samples can be taken without consent from people who are arrested if there are "reasonable grounds for believing they are involved in a recordable offence (ie one for which they could serve a custodial sentence)".

Few refuse because to do so may encourage police suspicions about their guilt.

At present authorisation for the forcible removal of a sample - usually using a mouth swab - has to be given by a superintendent.

But Mr Straw is proposing reducing this to an officer of inspector rank.

Critics say the changes to the DNA system could have far-reaching consequences and may discourage innocent men from volunteering their samples during murder or rape inquiries.

Safeguard

For example, if someone volunteers their DNA in good faith in response to a large-scale police search for a rapist or a murderer, they could find themselves convicted years later of a relatively minor offence based on the sample they had given.

Mr Straw has introduced a safeguard to protect against just this eventuality. DNA from people who gave offered samples simply for elimination purposes can only be kept by police if the donor gives his or her written consent.

But civil liberties groups are still not happy.

A spokeswoman for Liberty, Deborah Clark, told the BBC: "We operate in this country on the basis that if you're guilty, you're guilty and you are innocent until proven guilty.

"Keeping people's records on DNA databases when they've been proved not to be guilty is appalling."

Mr Straw denies his proposal was an attack on civil liberties.

DNA tests are used in the US to solve old crimes

He said the introduction of closed circuit television in streets and shopping centres had been seen at the time as an attack on civil liberties but was now welcomed by the public.

"We are already investing £143m in expanding the national DNA database, recognising the very significant contribution that DNA is making to identifying the perpetrators of what are often very unpleasant crimes.

The change was welcomed by the Chief Constable of Cambridgeshire, Ben Gunn, who is the Association of Chief Police Officers' forensic science spokesman.

Mr Gunn told BBC News Online: "The civil liberties argument is one which has been around since the DNA database was created in 1995."

He said there had been 134,812 "hits" on the DNA database since 1995, leading to thousands of people being convicted of charges ranging from burglary and car crime to murder.

But Mr Gunn said: "While DNA can help to prove guilt, it can also prove someone's innocence. It has been used to clear individuals who, for whatever reason, have been accused of serious crimes."

'Not retrospective'

He said there were around three million "active criminals" in the UK and it would have taken about 14 years to put them all on the database, had this step not been taken.

Mr Gunn said the new legislation could not be used retrospectively.

He said further enlargement of the database - to include every adult - was "not on on ACPO's agenda".

Mr Gunn said the change in the law would prevent a repetition of the "barmy" situation which led to a rapist and a murderer walking free after judges ruled that DNA samples which had been taken and retained after previous cases - which resulted in acquittals - could not be used in evidence at their trials.

But Professor Ian Shaw, who runs a forensic science course at the University of Central Lancashire, says there are dangers in expanding the database.

< Although the chances are remote, "the more samples you get, the greater the chance that you find two samples that look the same but are not actually from the same person", he says.