Lundy retrial: Shirt stain 'could be anything'

Mark Lundy, 56, has been defending charges that he killed his wife Christine and daughter Amber in the early hours of August 30, 2000 at their Palmerston North home. Photo / Mark Mitchell

Key evidence
• A defence expert has agreed that stains on Mark Lundy's shirt contain central nervous system tissue
• Another sample from the shirt was too degraded to know where the cells came from
• Electron microscopy and immunohistochemistry tests on the stains on the pocket and left sleeve of the shirt found the substance was typical of central nervous system tissue, which would have come from the brain or spinal cord
• Blood vessels were discovered in the stain
• It was difficult to transfer small amounts of brain tissue to different surfaces, but larger amounts were possible if the sticky inner was exposed
• The tests done on the stains could not say whether the cells were human or non-human.

Defence and prosecution witnesses in the Mark Lundy double-murder trial agree the substance found on his stained polo shirt is tissue from the central nervous system -- but they could not say if the tissue was human or not.

The jury trial in the High Court at Wellington today refocused on the stains on Lundy's shirt.

The Crown's case is that the stains on the shirt contained brain tissue from his wife Christine.

Lundy, 56, has denied killing his 38-year-old wife and 7-year-old daughter Amber in the early hours of August 30, 2000 in their Palmerston North home.

Defence witness, neuropathologist Colin Smith from the University of Edinburgh, agreed with prosecution lawyer Philip Morgan that there was no doubt the cells in the stains were from either the brain or spinal cord.

"If 100 pathologists looked at those slides they would agree, right?" Mr Morgan asked.

"I don't know about all of them but most probably would," Dr Smith said.

Another sample that had been dabbed off the top of the cells was too degraded to know what it was, he said.

"It could be anything."

The substance was "academic" however as there was no argument that the cells underneath the sample dabbed off was from the central nervous system, Dr Smith said.

Also giving evidence today was British-based forensic neuropathologist Daniel du Plessis, who told the jury it was "overwhelmingly, incontrovertibly incontestable" that tissue was from the brain or spinal cord.

His tests -- immunohistochemistry that identifies proteins present in different parts of the body and electron microscopy that magnifies images by up to 400,000 times -- confirmed the tissue came from either the brain or spinal cord, he said.

Dr du Plessis saw "copious" amounts of blood vessels, which were typically found within brain tissue.

"There's no doubt this is riddled with blood vessels," he said.

He also conducted a "crude" experiment to see how easy it was to transfer brain matter onto fabric.

The defence case was that the tissue could have been transferred onto Lundy's top through contamination.

Small pieces of tissue about 1-2mm would harden quickly and not be easy to transfer, but larger samples with a sticky inside could be transferred once the toughened outside flaked off, Dr du Plessis said.

"It's like French cheese that has a crust on the outside but oozes in the middle. It's very difficult to make the crust stick."

Defence lawyer David Hislop asked Dr du Plessis if he could tell if the tissue was human or non-human.

Dr du Plessis replied he did not know.

Mr Hislop then asked if he knew whether the tissue belonged to a male or female.

Again, Dr du Plessis said he did not know.

Skin flakes were also found on the shirt stains, but he said it was not known who they belonged to.

"It's not surprising to find skin flakes in a worn garment," he said.

The jury trial before Justice Simon France continues.