BBC News (November 2007)


By Julian Joyce, BBC News

It was a single, tiny speck of evidence and it was visible only under a powerful microscope.

Yet, discovered in Barry George’s coat, it was enough to convince a jury in 2001 that he was the murderer of TV presenter Jill Dando.

But what was that evidence – and how significant do experts consider it now? These are the questions that Appeal Court judges are considering as they decide whether or not to allow George’s appeal.

They will be guided by new advice from the government’s own forensic scientists – who now say relying on that single speck could be legally unsafe.

Microscopic particles

Central to the judges’ deliberations will be the nature of the speck. Known as Firearms Discharge Residue (FDR), it is the term given to the microscopic particles that spray out every time a gun is fired.

It is composed of bits of “propellant”, or gunpowder, that shoots the bullet, and also particles of the “primer” or percussion cap. The two kinds of residue differ in chemical composition: primer particles contain certain metals that distinguish them from propellant particles.

If we find someone with wedding confetti all over their hair and shoulders we can probably assume that they have gone to a wedding. However, if we find just one bit of confetti in their pocket then those assumptions become a lot more difficult to make.

David Dyson, independent firearms consultant

In George’s case the particle was discovered to be residue from the primer – meaning that it was made up of explosive with bits of metal inside it. Prosecuting lawyers at the time trial linked bits of FDR found on Jill Dando’s hair and body to a single particle of FDR found in George’s inside coat pocket.

They argued that it could only have come from the same gun that killed Jill Dando.

However, experts say that FDR is not like DNA or fingerprints, in that it does not have its own unique signature. In fact, FDR is generally divided into just five main “Types” according to the metals present. Type 1 FDR contains lead, barium, and antimony; Type 2 FDR contains those metals, plus aluminium, and so on.

Blood groups

Independent Firearms consultant David Dyson likens FDR classification to the way doctors classify blood groups.

“If we find type O blood traces at a murder scene, we might conclude that the murderer had type O blood – but so do lots of people. We could not narrow it down further than that.

“In the same way, we might analyse some FDR and conclude that it is Type 1. We might be able to trace it to a particular factory – but that factory might produce millions of rounds, all with the same chemical signature.”

A recent Panorama investigation into the Barry George case estimated that the particle found in George’s pocket could have come from any one of 230m cartridges.

Appeal court judges are also looking at the other vital aspect of FDR evidence – the fact that prosecutors made their case on the basis of a single particle.

Speaking on Panorama, former senior Metropolitan Police officer Peter Kirkham said he thought it was “doubtful” that George would have been charged at all, if it had not been for the FDR evidence.


But some experts now say that the risk of cross-contamination is so great that it was unwise to rely on a single particle to prove George’s guilt.

Former Forensic Science Service investigator Dr John Lloyd gave evidence in Barry George’s original defence. He told Panorama: “The essence of my evidence was that the particle should not have had any evidential significance attached to it. Accidentally occurring particles do occur on people in the situation of Barry George.”


  • Type 1 : Pb-Ba-Sb
  • Type 2 : Pb-Ba-Sb-Al + Ba-Al
  • Type 3 : Pb-Ba-Sb-Sn + Ba-Sb-Sn
  • Type 4 : Pb-Ba-Ca-Si with or without Sb
  • Type 5 : Ba-Ca-Si-Sn with or without Pb
  • Key : Pb = lead; Ba = Barium; Sb = Antimony; Al = Aluminium;
    Sn = Tin; Ca = Calcium; Sl = Silicon

George’s lawyers argued that the particle might have found its way into his coat from an army surplus shop, when he tried to join a gun club, or even by the accidental contamination of police officers who searched the flat.

Gun expert David Dyson confirmed that the more particles of FDR that are present, the more compelling it is as evidence. Conversely, the fewer particles, the less reliable FDR becomes.

Wedding confetti

“It’s like wedding confetti,” he said. “If we find someone with bits of confetti all over their hair and shoulders we can probably assume that they have gone to a wedding.

“However, if we find just one bit of confetti in their pocket then those assumptions become a lot more difficult to make.

“Did they go to a wedding – or did they pick up the confetti from someone they met in a pub who had gone to a wedding?”

Six years after Barry George was sentenced, the police’s own forensic scientists now seem to have come around to this argument.

Panorama revealed that a Forensic Science Service’s (FSS) report submitted to the appeal judges concluded that the single particle of FDR “was just as likely” to be recovered from George’s coat – whether or not he was the killer of Jill Dando.

Changed guidelines

A spokeswomen for the FSS confirmed on Wednesday that the service changed the guidelines it issued to its scientists last year.

A single particle of FDR is now no longer considered significant and has “no evidential value”, she said.

If the judges accept the FSS conclusions, it may be that an important part of the prosecution case against Barry George is fatally weakened.

And if that happens, there’s a good chance the conviction against the 47-year-old will be quashed.

See the original story on the BBC website here.

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