Mark Lundy is not a laboratory rat and his freedom should not be dictated by an untested scientific test, the High Court at Wellington has been told.
Mark Lundy, 56, is accused of murdering his 38-year-old wife and seven-year-old daughter, whose bodies were found in their Palmerston North home on 30 August 2000; the Crown claims Mr Lundy killed his wife for her insurance money and Amber because she saw what he was doing to her mother.
The prosecution and defence have wound up more than six weeks of evidence. Crown prosecutor Philip Morgan, QC, has presented his closing argument and lead defence lawyer David Hislop, QC, is giving his.
Mr Hislop said a brainplex developed by the Netherlands Forensic Institute used to conclude matter on Mr Lundy's polo shirt was human central nervous system (CNS) tissue from the brain or spinal cord, was untested and a developing science.
"It's not there yet."
"(It's) this man's life. He's not a laboratory rat, someone to try something out on."
International expert and defence witness Professor Stephen Bustin had told the court it would be folly to rely on the brainplex as it was not fit for purpose, and it would be foolish for the jury not to take heed of that, Mr Hislop said.
Mr Hislop had already argued it was impossible for Mr Lundy to be in Palmerston North the night his family was killed and said whatever was on his shirt got there in a way consistent with his innocence.
"It's either contamination or its central nervous system which is not human," he said.
"Forget the notion of a hunter. Forget the notion of an offal eater and deal with the hard evidence.
"He's a cook, and we know what's in chops, especially neck chops, in this country."
A witness had previously told the court spinal cord tissue was often found in lamb neck chops.
The bodies were found by Mrs Lundy's brother, Glenn Weggery, and Mr Hislop put it to Mr Weggery on day two of the trial that he killed them - something he vehemently denied.
Today Mr Hislop told the jury it was not his job to prosecute Mr Weggery but that he needed to show how the police had had tunnel vision and focused on Mr Lundy, and that stopped them looking further.
The prosecution had argued that the ferocity of the attack meant it could not have been random but Mr Hislop said that was simply idle speculation, as murders were committed by violent and sometimes deranged people.
"The fact that the killing was frenzied does not help to identify the killer," he said.
"The fact that the killer leaves behind no traces does not help to identify the killer."
Mr Hislop said there was no doubt the family was under financial pressure but claimed nothing would be achieved by killing Mrs Lundy, who was the mainstay of their kitchen sink business.
"Why would he kill the goose that laid the golden egg?"
"She was the mainstay of that business. He was the salesman. She brought the money in."
Mr Hislop accused the prosecution of desperation with their presentation of a criminal, Witness X, who claimed Mr Lundy told him he would not be in jail if his daughter had not seen what he was doing to his wife.
Witness X claimed Mr Lundy said his wife had it coming to her and that he had been planning his crime for some time.
But Mr Hislop said Witness X was dishonest, highly manipulative and wanted to work the system in his favour.
"Maybe it gives us a message about the state of their case," he said.
"One could almost hear the nails of the learned prosecutors scraping on the bottom of the barrel."
Witness X had denied being motivated by anything other than a sense of obligation to society but Mr Hislop said that was nonsense, and that he wanted to buy an easier time for himself next time he was in prison.
"Give a dog a biscuit each time he sits and he's going to expect a biscuit next time he sits," he said.
Mr Hislop said the trial had been a long journey.
"The petrol tells you he didn't do it. The stomach contents tell you he didn't do it. The open door tells you he didn't do it.
"Human nature tells you he didn't do it.
"We say in the case of Mark Lundy, that the only right verdicts, the only safe verdicts, are those of not guilty."
Justice Simon France will sum up on Monday and the jury will then retire to consider its verdict.
*Clarification - For the avoidance of doubt, please note that Radio New Zealand reporter Sharon Lundy is no relation to Mark Lundy.