The Lundy murder trial last week moved from the scene to the science, from blood patterns to barking dogs, from human to animal DNA.
Mark Lundy, 56, is accused of murdering his 38-year-old wife, Christine, and seven-year-old daughter, Amber, 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.
Mr Lundy's retrial, before Justice Simon France and a jury of seven men and five women, today enters its fifth week in the High Court at Wellington.
Prosecution witness Rodney Miller will start the week with his evidence, given via audio visual link from the United States.
Dr Miller, a pathologist, examined matter found on Mr Lundy's polo shirt which has subsequently been identified as being central nervous system tissue from Mrs Lundy's brain or spinal cord. The prosecution claims it got there because Mr Lundy was the killer; the defence maintains contamination was the culprit.
KEY WITNESSES FROM WEEK THREE
Inspector Ross Grantham was a detective sergeant in 2000 and the officer in charge of the Lundy homicide investigation.
He was questioned about a canvass of the Lundy neighbourhood which turned up tales of barking dogs - one described as "nutting off" - of a high-pitched female cry, of a sighting of a strange man in the area the night before the bodies were found. The defence asked Mr Grantham whether the reports were followed up or not, claiming they did not fit the then prosecution case that Mrs Lundy and Amber died within two hours of eating McDonalds for their dinner, based on the pathologist's opinion that was what had happened.
Mr Grantham admitted that was a focus of the inquiry but not the sole focus, that anything considered of interest was followed up. However, he could not remember specifics as he had not seen the file since 2003.
Mr Grantham told of keeping samples from Mr Lundy's polo shirt in his office safe rather than with other samples, as was usual, and then taking them to Dr Miller in the United States for examination. He denied there was any impropriety in doing it that way.
He also told of seeking a Wellington neuropathologist's opinion to try to identify a sample but denied he had said it was too degenerated for a result.
Mr Lundy had sought a meeting with police on 4 December 2000 to ask about progress on the inquiry, during which Mr Grantham asked if he would agree to the re-examination of his car and a suit bag, which had been found in the car. He "readily" agreed to both requests, and also volunteered he owned a tomahawk which would be either in his garage or in a storage lockup.
"I left with the accused stating he wanted to help us in any way he could," Mr Grantham said.
British blood pattern analyst and crime scene expert Gillian Leak worked for the British equivalent of New Zealand's Institute of Environmental and Scientific Research for 34 years until it closed in 2012. Cases she worked on included that of British serial killer Peter Sutcliffe, known as the Yorkshire Ripper, who was convicted of killing 13 women and attempting to murder seven others.
The defence witness was called while the prosecution was still presenting its case as she needed to return to Britain.
Ms Leak repeatedly raised concerns about the possibility those investigating the deaths could have contaminated evidence and said crime scene investigation methods had moved on substantially since 2000 as DNA identification had advanced and become more important in cases.
She said all investigators in the house should have "gowned up" at the outer cordon and entered and exited via a different door to the one identified as the killer's likely route; instead, they used the same entry and exit point and set up a changing area just by it.
As well, smears of blood found on a window by the conservatory door could have been caused by investigators losing their balance as they changed and reaching out to steady themselves, she said.
Ms Leak repeatedly said evidence could have been contaminated.
An officer who sat in a car next to the person who first found the bodies and accompanied him to the police station - before overseeing the collection of Mr Lundy's car and handing the keys to another officer, who reached into the car to steer it and let the handbrake off - could have left matter in Mr Lundy's car, she said. The matter could then have found its way on to a polo shirt in a suit bag in the car.
Justice France put it to Ms Leak that "everything has a potential risk".
"When you're dealing with exhibits from people movement at a crime scene ... would your answer ever be no," he asked.
Ms Leak agreed it would "probably never be no" because all options had to be considered.
Laetitia Sijen is head of research and development in the human biological traces team of the Netherlands Forensic Institute (NFI) and has given evidence at war crimes tribunals.
She used her department's newly developed "brain plex" to conclude the substance on Mr Lundy's polo shirt came from Mrs Lundy's brain; the defence attacked the brain plex as being untested and unreliable.
Dr Sijen admitted further testing could have given different results but insisted the overall result would have been the same; that the substance was brain.
The defence also attacked the NFI's error rate but the prosecution produced evidence to show it was only 0.4 percent - or 572 of the 132,456 samples tested in 2012 - and that those errors detected included such things as spelling mistakes in reports.
Elizabeth Wictum, who recently retired as director of veterinary laboratory forensics at the University of California, said she looked at three vials of DNA from New Zealand Institute of Environmental and Scientific Research. The samples were taken from smears on Mr Lundy's polo shirt.
She said the tissue contained traces of pig, beef and sheep DNA but that the positives were weak, meaning the source could have been processed food, such as sausages.
Mrs Wictum's lab did not report on human DNA but the marker for human DNA showed up as a "large peak" in the tests, she said.
Sergeant Robin Walker, who was the Palmerston North police photographer in 2000, told the court he wore paper overalls, as well as gloves and booties, when he took photos at the Lundy family home on 31 August and 1 September.
He changed them every few hours, and the used ones were disposed of in a rubbish bin, he said.
However, under cross examination by defence lawyer David Hislop, QC, Mr Walker admitted he sometimes put the same overalls on after taking a break and that he sometimes wore his protective gear out to his van to get gear before going back into the house.
Mr Walker was involved in the examination of Mr Lundy's car at the Palmerston North police station on 3 September and said he wore gloves to take photos of it but not full protective gear. He could not remember what others involved in the examination wore, he said.
* Clarification - For the avoidance of doubt, please note that Radio New Zealand reporter Sharon Lundy is no relation to Mark Lundy.