Scotland Yard has recovered DNA profiles of suspected sex offenders in eight out of ten unsolved rape cases dating back as far as 1987.
The "cold case reviews" have been made possible because material from rape and serious sexual offence cases is kept in secure police storage indefinitely and by recent advances in forensic science analysis. Scientists are thus now able to obtain DNA from tiny quantities of samples not detectable at the time of the offence and which are on clothes and other material seized from the crime scene, such as bedsheets.
Detectives have described the 84 per cent success rate in obtaining DNA of suspected rapists as "astonishing". The prospect is raised of catching and jailing hundreds of offenders years after they committed the attacks.
Several rapists have already been imprisoned and officers believe that they will soon identify a number of unconvicted serial attackers. In a second force, Northumbria, the police have recovered DNA profiles in almost half the cases they have examined since February 2002. So far they have obtained 60 genetic samples - 26 of which matched details of offenders kept on the national DNA database - out of 130.
Nine months ago the Metropolitan Police began to re-examine some of the 1,500 unsolved rapes and serious sex assaults that took place between 1987 and 1999.
Of the first 50 cases they re-examined, 15 produced profiles that matched known offenders among the 2 million DNA samples held on the national database. A further 20 have produced DNA profiles of suspects whom the police have yet to identify, and in eight cases there were mixed results in which several DNA profiles were obtained, which could include the offender. In only seven of the 50 investigations run as part of Operation Sapphire did the forensic scientists draw a blank.
Improvements in retrieving finger and palm prints have also helped detectives to gather fresh evidence, although the police stress that having laboratory evidence alone is not enough to obtain a conviction. It needs to be supported by other material such as witness and victim statements, although this can be extremely difficult in historic cases because many of those involved may have died.
The Northumbria force set up Operation Phoenix in February 2002 and secured its first conviction in January 2003.
As well as the conviction, five people have been charged, ten people have been arrested while further inquiries are made and a number of other cases are currently under development.
Commander John Yates of the Metropolitan Police's territorial policing unit said: "People who have raped and thought they had got away with it, will now have to think again."
The cold case review system for rapes is expected to be adopted by other police forces. The conviction rate in rape cases has fallen to a record low of 5.8 per cent. In the year ending April 2002 there were 9,743 recorded rapes in England and Wales.
Nationally there were 70,000 allegations of rape between 1986 and 1999 and with advances in technology the police are hoping to solve a substantial number of these cases in the next few years.
BROUGHT TO JUSTICE, 14 YEARS ON
A man who raped a French au pair in church grounds in 1989 was jailed for eight years in August after a successful "cold case" review by the Metropolitan Police.
Nick Keall, above, was charged after DNA taken during an arrest for assault in December 2001 matched the profile from the rape scene. Keall, 41, raped the au pair, then aged 21, as she walked home.
The court was told the attack ruined the life of his victim, who now lives in Belgium. She travelled over for the trial and said afterwards: "Since what he did to me, my life has been hell. Now it is over for me and it starts for him."Reuse content