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Last Updated: Sunday, 23 December 2007, 11:00 GMT
DNA test halted after Omagh case
Computer model of DNA structure
DNA testing can help the CPS build up its court cases
Police have suspended the use of a controversial DNA technique following the Omagh bomb verdict.

Earlier, the Crown Prosecution Service said it would review live prosecutions in England and Wales using Low Copy Number (LCN) DNA testing.

Northern Ireland's Chief Constable, Sir Hugh Orde, also said he had instigated an immediate review of cases there.

Omagh suspect Sean Hoey was cleared on Thursday of a total of 58 charges, including 29 murders.

Tony Lake, spokesman for the Association of Chief Police Officers (Acpo), announced the interim suspension of the use of LCN DNA testing by the Forensic Science Service (FSS).

He said: "In England and Wales DNA evidence has to be corroborated by other evidence.

"However, as a precautionary measure the Crown Prosecution Service are currently reviewing the pending cases in which Low Copy DNA profiling is to form part of the prosecution case to see whether any may be affected.

"The review will take into account the terms of the judgement and the weight that is to be attached to the DNA evidence."

The BBC's Michael Buchanan said that Acpo produced a confidential report in August which called for the technique to be urgently reviewed.

Tiny samples

The independent forensic science regulator will be carrying out the review.

It is a vital ingredient of cases in the future which will bring very guilty people to justice
Chief Constable Hugh Orde

The post was created by the Home Office in July this year to monitor the standards of evidence provided by the FSS and other private sector companies.

LCN allows genetic profiles of offenders to be created from very small tissue samples that have only been detectable with new techniques available since 1999.

These can be as tiny as a millionth the size of a grain of salt which can amount to as little as a few cells of skin or sweat left in a fingerprint.

The FSS say they have used LCN DNA about 21,000 times and generated profiles from items such as matchsticks, weapon handles and grabbed clothing.

To do this, the minute samples must be magnified and this is where critics say error can creep in.

The prosecution in the Omagh case claimed that LCN analysis had shown links between the bomb timers used in the attack and Mr Hoey, a south Armagh electrician.

But the judge rejected the use of the technique because it was not yet seen to be at a sufficiently scientific level to be considered evidence.

Following widespread criticism of Northern Ireland police by relatives of Omagh victims, Sir Hugh said: "I have asked for an urgent review of all cases that rely in any way, shape or form on Low Copy Number DNA."

He said it was at the very cutting edge of science and had been used in the trial because of his determination to build a case.

But Sir Hugh said: "It is a vital ingredient of cases in the future which will bring very guilty people to justice."

A spokesman for the Attorney General said that while a small number of active cases would be reviewed as a precaution, there were "no current plans to review past cases".

Previous cases

LCN testing has been used in a number of other high-profile cases.

It has been reported that it was this technique which was used by the FSS in Birmingham to examine DNA samples from the car hired by the McCanns.

Serial rapist Antoni Imiela was caught after his profile was obtained from minute traces of DNA from items of clothing.

And in 2000 Ian Lowther was convicted of the murder of Mary Gregson, who was walking along the Leeds-Liverpool canal towpath in August 1977.

The DNA LCN technique allowed scientists to go back and generate a DNA profile from an old semen stain originally found on the clothing.

Traditional or so-called "gold standard" DNA profiles created using larger samples of genetic material will not be examined under the review.

Michael Buchanan said LCN DNA was only accepted as evidence in two other countries, New Zealand and the Netherlands, because of concerns over its accuracy.

The debate over Low Copy Number DNA


Sean Hoey Why case unravelled
Kevin Connolly examines the Omagh bomb trial











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