Mark Lundy's final bid to overturn his convictions for murdering his wife and daughter has begun in Wellington today.
His lawyer, Jonathan Eaton QC, started by telling the judges Lundy's name was synonymous with miscarriage of justice.
Lundy was previously convicted of killing wife Christine 38, and 7-year-old daughter Amber at their Palmerston North home in August 2000.
This morning's Supreme Court hearing is the latest in a long string of appeals, and hangs on a single point - whether the Court of Appeal was wrong in choosing not to overturn the convictions when part of the evidence used to secure them was found to be inadmissible.
Eaton criticised the use of mRNA evidence at an earlier hearing, calling it "novel and junk science".
The evidence was used to tell the jury the brain or spinal tissue found in tiny specks on Lundy's shirt was likely human, rather than from an animal.
The method for analysing the brain tissue had "never been used before, never been used again", and the evidence based off it had been found inadmissible by an earlier court ruling.
"The name Mark Lundy has become synonymous with flawed expert opinion, flawed science and miscarriage of justice," Eaton said in today's hearing.
The Crown dug up the mRNA evidence after the Privy Council decision to "fill a gap" in the science linking Lundy to the murders, he said.
"Once you've got the link that it's human, it's game over."
The defence spent months before the second trial arguing the evidence should not be used, and it was "too overwhelming" to significantly challenge it at trial, he said.
Lundy's defence was that it was impossible for him to have committed the crime because of timings and his lack of fuel, but the Crown used the mRNA evidence to "taint" his defences.
Christine and Amber Lundy were found hacked to death at their home, likely with an axe or tomahawk. The murder weapon was never found.
On the night of their murders Lundy had checked into a motel in Petone where he called an escort about 11.30pm.
It was fiercely contested during his first trial whether or not it was physically possible for Lundy to have travelled between Wellington and his family home in a time that would have allowed him to be in the house at the time of the murders.
But Eaton today said another theory had never been explained.
"How on earth could Mark Lundy have carried out the crime as alleged and managed to rid himself of any forensic connection other than these two tiny spots on his shirt?"
The only evidence that linked Lundy to the crime was the shirt he was wearing the night of the murder, with its two small spots of central nervous tissue, Eaton said.
He questioned how Lundy could have disposed of any other shred of forensic evidence before getting into his car.
Crown lawyer, Philip Morgan QC, said there were two key bits of evidence at the retrial – the DNA and the fact that the material on the shirt was tissue from the central nervous system.
"Everything else was an add-on," he said.
"There is, in my submission, nothing fundamentally wrong at all with the Court of Appeal doing just exactly what it did."
The defence had not been able to provide a clear narrative as to how brain or spinal tissue had ended up on two different spots on his shirt from food, he said.
It was an "extraordinarily unlikely coincidence" for Lundy to have ended up with "fresh central nervous system tissue" on his shirt in two places, and for the only DNA to have come out of those spots to be from Christine Lundy.
He said there were not "trace amounts" of DNA either – it was "high quality" and there was "a lot of it", and it was consistent with blood or tissue.
The court cases
Lundy was first convicted of the murders in 2002, and his first appeal attempt resulted in the court increasing the non-parole period of his life sentence to 20 years.
His conviction was quashed by the Privy Council in 2013, which ruled there were problems with the analysis of the brain tissue found on Lundy's shirt, as well as with the time of death.
In a 2015 retrial at the High Court in Wellington, Lundy was again convicted of the murders.
He appealed to the Court of Appeal last year, which found the evidence around the brain tissue should not have been presented to the jury, but decided to uphold the convictions anyway.
The Crown argued Christine Lundy's brain tissue was found on the polo shirt her husband wore on the night of the murders.
Tiny spots consistent with dried blood were also found on the shirt, which were found to contain Amber's DNA.
The hearing will continue tomorrow.