Erin Patterson did not answer when asked if she picked the mushrooms herself, court told
Katrina Cripps says during the home visit, Erin Patterson described the packaging of the dried mushrooms to her as “in a bag that was not re-sealable” with a white label.
Patterson said she had opened the bag previously but decided to not use the dried mushrooms, Cripps says.
Patterson said she had been planning to use them in a carbonara dish but had decided against it as they had a “strong smell”, Cripps says. She then placed them in a container, the court hears.
She says Patterson told her she decided to use the mushrooms with the strong smell in the beef wellington meal because they “wouldn’t be the primary flavour”.
Cripps says she asked Patterson if she picked the mushrooms used in the dish.
Prosecutor Sarah Lenthall asks Cripps if Patterson answered the question.
Cripps says she did not. She says Patterson was on her phone when she asked the question.
Key events
Jurors are shown the toxicology results for Patterson’s mother-in-law, Gail Patterson.
Gerostamoulos tells the court the institute received more than 50 antemortem samples from Dandenong Hospital and the Austin Hospital.
He says no urine was collected or suitable for analysis.
Gerostamoulos says the results show no detection of alpha-amanitin and beta-amanitin above the reportable threshold in any of blood specimens.
Gerostamoulos confirms he was sent antemortem and postmortem samples for Patterson’s father-in-law, Don Patterson.
He tells the court samples included stomach contents, a small section of liver and fluid from the eye.
He confirms a number of the specimens were tested for alpha-amanitin and beta-amanitin.
The jury is shown a table of the toxicology results for Don Patterson.
Prosecutor Sarah Lenthall asks Gerostamoulos about the results.
An antemortem urine sample shows a “clear detection” of alpha-amanitin and beta-amanitin, the court hears.
Gerostamoulos says postmortem blood and serum samples, collected days after Don presented to hospital, did not detect alpha-amanitin and beta-amanitin.
He tells the court when blood samples are collected after 24 hours of ingestion, they are unlikely to show levels of alpha-amanitin and beta-amanitin.
He says:
We know they persist in urine for some time longer.
Gerostamoulos says the institute’s laboratory has a “reportable threshold” when testing a specimen for the presence of a compound. This is a concentration that can be reliably and repeatedly reported in a specimen, he tells the court.
He says if it falls below the threshold it is reported as “not detected”.
The reportable threshold for alpha-amanitin and beta-amanitin in samples like blood is “0.5 nanograms per mL”, he says.
Gerostamoulos tells the court testing for these toxins requires specialised techniques. He says:
We developed a technique that we know works reliably.
Gerostamoulos confirms the institute received a range of specimens for testing in this case.
He says these included antemortem, taken while the person is alive, and postmortem samples, taken when the person has died.
Samples collected soon after the ingestion are the most reliable.
Gerostamoulos tells the court the lethal dose of amatoxins for a 70kg adult would be about three tablespoons.
But he says the exact lethal dose will “depend on how much of the toxins are there”.
Gerostamoulos says the studies have been conducted in animals including mice and dogs.
He says:
They’re very toxic compounds.
Gerostamoulos says a small amount of amatoxins are found in the death cap mushrooms. He says:
Less than 10% of the mushroom actually contains the alpha-amanitin and beta-amanitin.
Gerostamoulos tells the court a person who has ingested the amatoxins will experience diarrhoea, vomiting and progressively get worse if a person is not treated.
He says the liver cannot process these amatoxins like a “normal drug”. He says:
Once a foreign drug is ingested, the body will look to remove that.
He says alpha-amanitin and beta-amanitin can be detected in the body when someone has ingested death cap mushrooms.
He says:
They have a very short half-life which means they don’t persist in the body for a long time.
He says the toxins may remain in the urine for a few days.
Gerostamoulos tells the court toxins in death cap mushrooms are not usually tested for at the institute.
He says when testing for death cap mushrooms the institute looks for the presence of amatoxins.
He says the amatoxins produced by death cap mushrooms are alpha-amanitin, beta-amanitin and to a lesser extent gamma-amanitin.
These can lead to a range of symptoms including liver failure and cell death, the court hears.
The prosecution has called their next witness, Dr Dimitri Gerostamoulos.
Gerostamoulos is the head of forensic science and chief toxicologist at the Victorian Institute of Forensic Medicine, the court hears.
Prosecutor Sarah Lenthall re-examines child protection worker Katrina Cripps.
She asks Cripps about her evidence regarding how much of the beef wellington meal Patterson consumed.
Cripps reviews the notes from the meeting with Patterson on 1 August 2023 – three days after the lethal lunch.
Lenthall asks how much of the meal Patterson told Cripps she ate.
“Half,” Cripps replies.
Cripps’ evidence concludes.
Court resumes in Patterson trial
The jurors have returned to the courtroom in Morwell.
The jurors have been sent out of the courtroom for an early lunch break.
The trial will resume at 2.15pm.
Sophie Stafford questions Katrina Cripps on her timeline about when Erin Patterson knew the parents of her estranged husband, Simon, were unwell after the lunch.
Stafford says Cripps has provided evidence about Patterson recalling two conversations with Simon to her on the Sunday and Monday after the lunch.
Regarding the conversation on Sunday, Stafford tells Cripps that Patterson “did not tell you that Simon had told her that the others were unwell at that time”.
Cripps replies:
You can suggest it but I’m certain.
