Convicted double murderer John Barlow's fight to clear his name goes on after what his lawyer Greg King called a "successful" first day hearing at London's Privy Council today.
The Commonwealth's highest court heard Mr King rubbish FBI forensic evidence that led a jury to send Barlow to prison for the murder of Wellington father and son Eugene and Gene Thomas, who were killed in 1994.
Mr King's first victory was for the five law lords to hear the petition for special leave to appeal, and to consider evidence the New Zealand Court of Appeal would not listen to when it denied Barlow an appeal in March 2008.
After the hearing Mr King said: "All we ever asked for in this case was for the opportunity for the case to be considered on its merits - and we've been successful because the Privy Council has given us that.
"We've been asking for that to happen for years but that has been denied us in New Zealand by the Governor-General and the Justice Minister."
Mr King told the law lords that crucial evidence relating to the weapon and bullets that killed the Thomas' had been falsely linked to Barlow, a former antiques dealer, who is serving 14 years for murder in Upper Hutt's Rimutaka Prison.
Mr King said evidence given by FBI agent Charles Peters had been proved to be flawed and that had unduly influenced the jury at Barlow's third trial after juries had failed to reach a verdict at two previous trials.
Mr Peters testified that forensic testing known as comparative lead bullet analysis showed bullets found at the crime scene matched those belonging to Barlow.
But the tests have since been discredited worldwide for providing a high number of false matches.
The Crown case in all three trials hinged on proving that Barlow's CZ27 pistol, and related bullets and a silencer, was the murder weapon.
Mr King said: "New Zealanders only know the FBI through the movies."
He said that "excitement" was "going to have an impact" on how much weight they gave Mr Peters' evidence.
He said Mr Peters had "talked in a language" the jury could not understand, and had impressed them by linking the bullets that killed the Thomas' with those dumped by Barlow at a tip after he feared they would link him to the murder.
Mr King said the crux of his argument lay in dismantling the linking of the source of the bullets that killed the Thomas' and those dumped at the tip, as well as evidence about the type of bullet used gained from black sealant from bullets found by forensic scientists.
The Crown had explained this by saying the sealant had been changed by passing through human tissue.
King said black sealant on the unusual Geco bullets that killed the Thomas' was different to bullets left at the landfill by Barlow after the murder.
Deputy Solicitor-General John Pike said King's "attack on the FBI agent was not so cogent as it would be otherwise", because there was evidence other than from FBI agent Mr Peters that the bullets used to kill the Thomas' came from Barlow.
Mr Pike agreed that Mr Peters' evidence was not as damning as it had been but said evidence from New Zealand scientist Peter Wilson and others showed the bullets were Barlow's.
He added that even "assuming the jury understood a word" of Mr Peters' complex forensic evidence, "it doesn't matter" because of the weight of other evidence linking the bullets to Barlow was overwhelming.
He added that Mr Peters' analysis only related to US bullets while the lead bullets in question were made by the German Genschow company.
But Mr King said outside court: "All Wilson's evidence was originally heard at Barlow's first two trials. If it was not good enough then, why is it now?"
Mr Pike said there were only 43 boxes in New Zealand of the "collectors' item" Geco bullets found in the murdered pair and the only scenario that would mean Barlow did not murder them was the "unlikely event" someone came to New Zealand and used "analytically indistinguishable bullets".
Mr Pike added that no one other than Barlow could be reasonably associated with the crime scene. He also linked a home made silencer found at the tip to the bullets and to Barlow.
Mr King said he would present 2000 pages of evidence for the law lords to consider over an estimated six weeks.
The hearing continues tomorrow after a false fire alarm at the court ended proceedings early.