Forensic scientist Dr John Bond has created a method of retrieving prints from bullets which have already been fired, raising the possibility that hundreds of "cold cases" could now be deciphered.

Earlier this month, the Chronicle & Echo exclusively revealed the technique was being used by US Marines in the hope of tracking down terrorists who plant bombs.

Meanwhile, three police forces in America and two in the UK are exploring whether the method could be used to find killers, and today Dr Bond will meet detectives from Kingsland, Georgia, in the hope of solving a 1999 double murder.

The forensic expert, who is leading the research for the University of Leicester and Northamptonshire Police, said: "All I know about this case is that it is a double murder.

"Beyond that I don't want to know because the more I know about the circumstances, the more it might influence what I'm looking for.

"We have already had some success at enhancing partial fingerprints on shell casings for other police forces, where the cases were some years old, and conventional fingerprinting techniques had been tried and failed."

The cold case review is being led by Detective Christopher King, of Kingsland Police Department, who was due to arrive in Northampton last night with evidence from the murder scene.

Det King said: "The suspect(s) in this case entered a downtown business in the early afternoon, shot and killed the two employees and stole a small amount of cash.

"Four fired shell casings ejected from the suspect's pistol were recovered at the scene, and have been processed for latent fingerprints using traditional methods of dusting and fuming, with negative results.

"We contacted Dr Bond and were invited to bring the evidence to Northampton for processing in the hope that, with the Leicester process, a latent fingerprint might be located on the actual casing itself, which would help to bring more evidence against a possible suspect.

"While we understand that there is no guarantee of positive results, every possibility must be explored to bring the suspects to justice and closure to the victims' families."