Monday, May 31, 1999 Published at 16:09 GMT 17:09 UK
Police given key to unsolved murders
Criminals cannot give alibis for their DNA
Hundreds of unsolved murders dating back 30 years could be cleared up by an advance in genetic fingerprinting which is being made available to police.
Detectives from all over the UK will soon have access to the technique which has been developed by the Forensic Science Service (FSS) in Birmingham.
Scientists have even managed to obtain sample material from watch straps, ear rings and even shirt collars.
There is even evidence that DNA material can be left over after a handshake.
50% success rate
In Australia, where the technique was pioneered, about 100 cases have been reopened and there have been at least 50 successful prosecutions.
The technique will also enable police to identify serial killers.
Detectives at the National Crime Faculty at Bramshill, Hampshire, have identified several "clusters" of unsolved murders which could be the work of the same individual.
Among them are a series of prostitute murders in London, the Midlands and Scotland.
Ever since the Polymerase chain reaction technique was first developed in the 1980s, scientists have been working on taking DNA from smaller and smaller pieces of evidence.
Police will now re-examine microscopic fragments which were previously thought to be too small to use.
Reopening old crimes
Scientists say they should be able to obtain genetic profiles from biological material - blood, saliva, hair or semen - taken from crime scenes up to 30 years ago.
DNA is a tough material by nature and researchers have been amazed by its stubborness.
A spokeswoman for the FFS said: "We will be looking at the same types of material in terms of biological traces but it means that even if there is not much of it, or it is degraded, the new technology gives a much, much better chance of getting a profile.
"It is more powerful, more sensitive and more discriminatory than before."
The new technique is to be made available next week and will allow police to reopen hundreds of unsolved cases .
Detectives in east London will want to re-examine the case of 11-year-old Nayntara Ali, who was murdered on her way home from school in Forest Gate, east London. Her body was found rolled up in a carpet in a disused yard.
Another high profile case which will no doubt be revisited is the Rachel Nickell murder on Wimbledon Common in 1992.
High profile cases
The FSS has been trialling its Low Copy Number (LCN) test since january, using samples of evidence from about 70 cases, mostly unsolved high profile murders and rapes.
But the new technique has yet to be tested in court and some independent forensic scientists fear it could be easily contaminated.
LCN is based on the work of Dr Roland Van Oorschot at the Victoria Forensic Science Service in Australia.