Update: Pollen grains recovered from Corryn Rayney’s nasal passage suggest she “took her last breaths” at her Kings Park grave site, her husband’s wilful murder heard today.
As the trial entered its twelfth week the court also heard from a top police officer that CCTV cameras covering the likely route between Kings Park and Mrs Rayney’s Como home were not working on the night she was killed.
Appearing at a witness for Lloyd Rayney’s defence team pollen expert Lynnette Milne said if Mrs Rayney had died at her Como home there would likely be some pollen consistent with that location in her nasal passage.
Instead, Dr Milne said, the only pollen present appeared to have come from Kings Park. Asked if the evidence suggested Mrs Rayney’s last breaths were at Kings Park Dr Milne said: “Yes that does.”
Dr Milne is a UWA academic and author of A Grain of Truth: How Pollen Brought a Murderer to Justice, which related the role played by forensic palynology in solving a murder case.
The prosecution alleges Mr Rayney killed his wife at home on the night of August 7, 2007, drove her body to Kings Park and abandoned her car in Subiaco before likely walking or running the 8km to his Como home.
The defence has suggested she could have been alive at Kings Park and may even have been buried alive.
Mr Rayney denies any involvement in his wife’s death.
Earlier the court heard from Det-Sen. Sgt Carlos Correia – the officer in charge of the investigation into Mrs Rayney’s death –that cameras at the Narrows Bridge “weren’t operable” on the night she died.
Justice Brian Martin had asked prosecutors to find out if CCTV footage was available, saying the Narrows Bridge would be the quickest route for someone travelling from Kings Park to Como.
No witness reported seeing Mr Rayney that night and no taxi driver had a record of picking him up.
The court also heard from another defence expert witness, Lorna Dawson, who was critical of the methods used by prosecution experts to show similarities between soil recovered from Mrs Rayney’s body and soil taken from outside her house.
Professor Dawson, who is head of forensic soil science at the James Hutton Institute in Aberdeen, gave evidence that soil from one location could never truly be “matched” to another.
“(Soil is) not like the DNA we were born with, there’s a huge amount of uncertainty with soils because they change they are mixed, they are moved about, you do not have the ability to match an unknown sample with a known sample,” Professor Dawson said.
She said given the soil found outside the Rayneys’ home was a common type of soil more locations should have been sampled as part of the investigation.
The fact that the minerals found in the soil were common and the type of methodology used was inorganic meant they had a "very lower power of discriminating between... sites", she said.
"So they were not powerful in giving any evidential value as to whether something could have come from... (a particular site) or not," she said.
The State has now effectively finished its case and the defence is expected to wrap up its case tomorrow with a series of tendered statements.
The trial will then likely adjourn for a fortnight before both sides begin their closing arguments.