Murder, rape and child abuse investigations will be hampered if a European court rules that more than 500,000 DNA samples should be removed from Britain’s National DNA Database, a senior police chief has told The Times.

In his first interview since standing down as chairman of the database, Tony Lake gave warning that serious crimes would go undetected if judges barred police from storing the DNA of people who had been arrested but not subsequently convicted of an offence.

Mr Lake, Chief Constable of Lincolnshire, urged ministers to consider all possible options if the court’s ruling went against Britain. “The law is the law. We have signed up to the European principles and I appreciate that it is very difficult for any government, but we must understand the level of risk that is created automatically when you start to filter and purge your DNA database,” he said.

Ministers’ options are limited because the case is being heard by the Grand Chamber of the European Court of Human Rights, the rulings of which are binding and impossible to challenge. The case was brought by two men from Sheffield who were arrested in 2001 and had their fingerprints and DNA samples taken. They argue that, because they were not convicted of any crime, the samples should now be destroyed. Their case has been rejected in the British courts but was heard by the European Court of Human Rights in February. A judgment is expected later this year.

Mr Lake, 57, who retires next week, said that the case was the most pertinent issue in forensic science and he dismissed the debate about creating a universal DNA database as a red herring. “You could argue that this is a manifesto issue. If there is a debate about expanding the database, then there should be a national debate about the consequences of cutting it. The country must understand that there will be an increased risk to our ability to solve crime.

“It would be potentially devastating. Without a doubt, it would prevent the detection of a variety of crimes, including some of the most serious.”

More than 8,000 people who were on the database because they had been arrested, but not convicted, have been found guilty of subsequent offences after their DNA was recovered from crime scenes. The cases have involved about 14,000 offences, including 114 murders, 55 attempted murders and 116 rapes.

The database holds 4.5 million samples and is by far the largest in Europe. About 60,000 personal samples are added to it every month and further unknown profiles are loaded from crime scenes. DNA samples, which are always supported in court by other corroborating evidence, played a key role in the conviction of Steve Wright, who killed five prostitutes in Ipswich, and Mark Dixie, the killer of the model Sally Anne Bowman. It has also helped police to solve “cold cases” including rape cases dating back decades. Mr Lake said: “There have been spectacular results in cases where lives have been shattered, where women have been afraid to walk out their front doors for fear of bumping into the man who raped them 10, 15 or 20 years before.”

The greatest unforeseen benefit of DNA advances, however, has been in solving so-called volume crime, such as burglaries, assaults and car thefts. Mr Lake said: “The public expectation now is that crime will be solved, not by the presence of witnesses, but because there will be DNA. It has stolen the limelight but we get more convictions through finding fingerprints. Other areas of forensic science are opening.”

His fear is that an adverse ruling would not only hurt the DNA database but also restrict the use of fingerprints and other intelligence databases. “The question would quickly become. ‘To what extent does the ruling apply to other databases?’.”

The key issue for Mr Lake is whether the court will consider the rights of victims properly. “People will accuse me of playing the emotional card. Well, I don’t do emotional blackmail. You have to think the unthinkable. I would not like to be the officer who has to look a parent in the eye and say, ‘We could have prevented this’.”


Equal treatment

The future of the world's most sophisticated DNA database is being considered by the Grand Chamber of the European Court of Human Rights, which draws its members from the nations of the Council of Europe.

The 17-judge panel trying the DNA case includes some with limited or no experience of DNA technology.

The complainants, Michael Marper, 45, and a 19-year-old man from Sheffield referred to only as S, are relying on article 8 (right to private life) and article 14 (prohibition of discrimination) of the convention.

The teenager had his DNA taken when he was arrested in 2001 and charged with attempted robbery. He was acquitted. Mr Marper, 45, was charged with harassing his partner but the case was later dropped. They argue “that as people without convictions who are no longer suspected criminals, they should be treated in the same way as the rest of the unconvicted population of the UK”.

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