Erin Patterson faces her sixth week on trial for three murders, accused of intentionally serving up a poisonous mushroom dish to her estranged husband’s family.

The 50-year-old’s defence team will continue to question the case’s lead investigator today, after he spent four days in the witness box last week.

Detective Senior Constable Stephen Eppingstall took the jury through evidence police had gathered from before and after Patterson cooked the meal on July 29, 2023, including her shopping list.

Her Woolworths transaction history, from July 23 to July 28, revealed she had bought about 1.7kg of mushrooms in the days before she made the fatal meal.

She also bought more than 4kg of fresh and frozen pastry and five beef eye fillet steaks for the individual beef Wellingtons, which the jury was told she had made from a RecipeTin Eats cookbook.

The prosecution showed the jury Patterson’s police interview, on the afternoon of August 5, 2023, after a search warrant at her home.

She was interviewed the day after two of her lunch guests, Gail Patterson and Heather Wilkinson, had died in hospital while the women’s husbands were both still fighting for their lives.

“We’re trying to understand why you’re not that ill,” Eppingstall said to Patterson, in video of the interview.

“But I’m sure you understand too that, like, I’ve never been in a situation like this before,” Patterson said.

“And I’ve been very, very helpful with the health department through the week because I wanted to help that side of things.”

Patterson then lied to the police, when asked if she owned a food dehydrator she said “no” and “I might’ve had one years ago”.

“When I got the Thermomix I got really excited about, like, making everything from scratch,” she said.

Her defence team admitted at the beginning of the trial this was a lie, as was her claim to police she had “never” foraged for mushrooms.

Patterson has pleaded not guilty to three counts of murder and one of attempted murder, with her lawyers claiming the death cap mushroom-laced meal was a “terrible accident”.

Her former in-laws, Don and Gail Patterson, 70, and Gail’s sister Heather Wilkinson, 66, all died in hospital days after eating the meal made by Patterson at her Leongatha home. Ian Wilkinson survived.

The trial before Justice Christopher Beale in the regional Victorian town of Morwell continues.