Anonymous evidence ruled unfair

The ruling could impact on the Met Police's Operation Trident

The Law Lords have ruled that a man convicted of a gun killing on the basis of evidence given by anonymous witnesses did not receive a fair trial.

Ian Davis was jailed in 2004 for murdering two men at a New Year's Eve party in Hackney, London, after three witnesses said he was the gunman.

The Law Lords' ruling means Davis can now appeal against his conviction.

The Metropolitan Police said it is "very concerned" by the ruling, which could impact on gang crime operations.

The BBC's Crime Correspondent Ben Ando said there could be repercussions for London's Trident operation, which tackles gun crime in the black community.

The use of anonymous witnesses in Operation Trident trials has led to several high profile convictions in recent months.

The Head of Operation Trident, Helen Ball, told BBC News: "People who think they have evidence to give often think twice about telling us about it because they don't want to put themselves in danger."

Feared reprisals

A Met Police spokesman said: "This case was exceptional by the fact that special measures were used for all of the witnesses; however, we will now be looking at the implications upon cases awaiting trial.

"We stand by the opinion that special measures are an invaluable tool for bringing witnesses to give evidence in exceptional circumstances, and the Met Police will continue to support these measures where possible."

He added that they have written to Justice Secretary Jack Straw and Home Secretary Jacqui Smith to see what legislative action can be taken.

We remain committed to the use of anonymous evidence in appropriate cases and believe it is an effective tool to tackle witness intimidation Ministry of Justice

The Law Lords said in their ruling: "No conviction should be based solely or to a decisive extent upon the statements and testimony of anonymous witnesses."

Davis' case will now be referred to the Court of Appeal to quash the conviction. The Crown Prosecution Service can apply for a retrial if it feels that adequate evidence remains, or offer no further evidence.

A CPS spokesman said they would "examine the ruling in detail and decide on its implications in due course".

During Davis' trial, the jury heard that after the shooting, he fled to the US on a false passport.

Three witnesses, who said they feared reprisals, identified him as the gunman and were allowed to give evidence anonymously.

Appropriate cases

Davis claimed he was the victim of false accusations from a jealous ex-partner but this defence was never explained to the jury because his lawyers could not make reference to the witnesses' possible identities.

In their ruling, the Law Lords argued it has been a fundamental principle of English Law that the accused should be able to see his accusers and challenge them.

They did however acknowledge the problems of witness intimidation and urged Parliament to examine the issue.

Malcolm Swift QC, who represented Davis, admitted the ruling was a blow to the prosecution.

But he said: "Eventually we would end up with trials of defendants on evidence that would have been given completely anonymously from witnesses who may well have axes to grind."

A Ministry of Justice spokesperson said: "We remain committed to the use of anonymous evidence in appropriate cases and believe it is an effective tool to tackle witness intimidation – particularly in cases involving gang and gun crime.

"We are studying the judgment carefully and considering its implications."