A British forensics expert's opinion paint fibres found in Christine Lundy's hair could have got there during a visit to the family garage has been attacked by the Crown.
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.
Key points from day 16:
- British forensics expert Gillian Leak said it was highly likely whoever attacked the Lundys would have been "substantially" covered with blood, bone and brain tissue.
- Blood found on a window at the Lundy family home could have been the result of contamination, as investigators used the door next to it to enter and exit the scene, Ms Leak said.
- Photos should have been taken of the stains such as the ones found on Mr Lundy's polo shirt, she said.
- Forensic scientist Bjorn Sutherland was "completely" confident he could discount the possibility he had unwittingly transferred Mrs Lundy's brain tissue from the crime scene to the Palmerston North Police Station, or from the post-mortem to the police station or the crime scene.
- However, Mr Sutherland could not discount the possibility Mrs Lundy's bodily tissue was transferred between investigators as she was put into a body bag.
The Crown is still presenting witnesses but defence witness Gillian Leak is giving evidence today as she needs to return to Britain.
Ms Leak, a blood pattern analyst and crime scene expert, worked for the British equivalent of New Zealand's Institute of Environmental and Scientific Research (ESR) for 34 years until it closed in 2012. One of the cases she worked was 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.
She told the High Court at Wellington a study had found hair retained fibres better than clothing; retention depended on how often the hair was washed and brushed, and long hair retained it best.
Flecks of the orange and blue paint were found in the blood and pieces of skull washed from Mrs Lundy's body, the sheet taken from her bed and in "debris" taken from Amber's body.
The prosecution had previously told of Mr Lundy's habit of painting his tools with orange and blue paint to identify them as his own and maintains the flecks found on the bodies and debris were from a tomahawk-like weapon used to kill them.
But Ms Leak yesterday said the paint flakes could be explained by Mrs Lundy going into a garage full of painted tools and getting the flecks in her hair, or from equipment used to decorate their spare room.
She said she would not rule out that it had come from the weapon "but you have a problem here - you don't have a weapon to compare it with".
As well, samples were taken only from and around the bodies but not the rest of the house, so the findings would have to be considered "neutral".
But Crown prosecutor Philip Morgan, QC, questioned Ms Leak's expertise on the matter and said she had only looked into it a week ago, after hearing ESR forensic scientist Bjorn Sutherland give evidence on it last week.
"Do you seriously suggest that that (the fragments) is due to Christine Lundy somehow getting paint fragments from the garage in her hair, going to bed that night with these paint fragments in her hair, and the attack with the implement transferring some paint fragments from her to Amber Lundy," he asked.
Ms Leak replied that she could not rule it out.
Earlier, Ms Leak said blood found on a window at the Lundy home could have been the result of contamination.
Ms Leak, who said she had lost count of how many crime scenes she had examined where brain matter was spread around the scene, said blood found on a window next to a sliding door found open after the deaths could have come from those investigating the crime. That was because, despite it being the likely point of entry for the assailant, it subsequently became the entry and exit for investigators.
"I don't think anybody can rule that out from what's been found so far," she said.
"I think that it [the scene] has been compromised given that the door was opened when the first person arrived, that that would be an area of forensic interest because there's a good chance [the offender] would have left behind something, anything - fibres, DNA."
In Britain, an outer cordon would have been set up at the perimeter of the property, as had happened at the Lundy home. However, unlike at the Lundy home, investigators would have changed into protective gear at that perimeter rather than by the house, as happened.
A video showed an investigator outside the home in a fabric overall, prompting Ms Leak's observation that science around DNA evidence had evolved so much in the past 10 to 15 years that anyone inside the outer cordon would be fully covered, including their head.
The trial continues in the High Court at Wellington before Justice Simon France and a jury of seven men and five women.
* Clarification - For the avoidance of doubt, please note that Radio New Zealand reporter Sharon Lundy is no relation to Mark Lundy.