Hundreds of unsolved crimes - including high-profile murder cases - could be re-investigated using revolutionary new forensics techniques, officers in East Anglia said last night.

Hundreds of unsolved crimes - including high-profile murder cases - could be re-investigated using revolutionary new forensics techniques, officers in East Anglia said last night.

The government-owned Forensic Science Service (FSS) yesterday announced a trial of the system which means previously uninterpretable DNA samples may now be used in evidence. It will be made available to Norfolk, Suffolk and Cambridgeshire within three months and officers are already assessing its potential impact.

In Norfolk, cold cases such as the murders of teenagers Natalie Pearman, Johanna Young and Susan Long could be re-examined. In all three the killers have so far evaded justice despite the existence of DNA evidence.

Detection rates for day-to-day offences such as thefts, burglaries and motor crime are also expected to be boosted.

Det Insp Mick Gent, from Norwich CID, said: “This new technique is going to have a significant impact both for future investigations and past ones.

“We use DNA profiling across the board to help us investigate a whole range of crimes, from thefts and burglaries to more serious assaults and murders.”

The technique, dubbed DNAboost, is currently being used by West Yorkshire, South Yorkshire, Northumbria and Humberside police. It is a world-first and means that when more than one person has touched a surface - a door handle, for instance - it will be possible to distinguish between individual samples.

This - combined with another method called Low Copy Number, which enables matches to be found using minute samples of cells - mean countless cases which have lain dormant for many years can be re-examined.

FSS scientists estimate that the breakthrough could double the number of cold cases which could now be solved.

Mr Gent said: “Currently some samples come back to us with what we would call a mixed profile - this means there is more than one person's DNA in the sample and it hasn't been possible to identify any individual.

“But with this new technique, our forensic specialists will now be able to separate the profiles and identify every single person.

“So, for example, if we were investigating an assault where a person had been punched several times by various different people - where once we may not have been able to separate the different profiles, now there is a good chance we would be able to identify every single person involved.

“Every contact leaves a trace and this puts us one step further down the line - it is going to be an invaluable tool in investigating a broad range of crimes and will mean we will be able to revisit older crimes and find new leads.”

Simon Stevens, a spokesman for Suffolk police, said: “We will look at how these forces progress with the trials with interest. Any advance in science which could help us solve more cases must be welcomed.”

Following the 1992 murder of Natalie Pearman, a 16-year-old prostitute from Mundesley whose body was found in a lay-by at Ringland Hills, police obtained a full DNA profile. The killer has not been found but Norfolk's Major Investigation Team has long-held hopes that forensic advancements could lead to a breakthrough.

In the killing of 14-year-old Johanna Young, from Watton, the same year, only a small amount of forensic evidence could be gathered. To date this has produced few leads but could now shed fresh light on the investigation.

The case of Susan Long, an 18-year-old Norwich Union worker from Aylsham, could prove more complicated as the crime happened 36 years ago. At the time, 220 people were eliminated using mouth swabs but DNA evidence still exists.

All three cases remain on file with Norfolk's Major Investigation Team.