An Australian woman has been found guilty of the 2023 murders of her sister and her in-laws, after serving them lunch laced with poisonous mushrooms.

A jury at the Supreme Court of Victoria convicted 50-year-old Erin Patterson of murder Monday, following six days of deliberation and a 10-week trial.

As CrimeOnline previously reported, the incident happened on July 29, 2023, at the defendant’s home in Leongatha, Victoria, after she invited the victims, Don Patterson, 70, Gail Patterson, 70, and Heather Wilkinson, 66, to lunch.

Patterson’s husband, Ian, also became ill after the lunch but survived after months of hospital treatment.

Patterson claimed innocence, telling investigators that she served the guests a beef Wellington steak dish with fresh mushrooms she bought at a supermarket, along with dried mushrooms she claimed she purchased at an Asian store in Melbourne.

Her defense team called the incident a “terrible accident” that happened when she tried to make the meat taste better with the mushroom mixture.

Patterson said she then panicked and lied to investigators, CNN reports.

The prosecution, however, said that “four calculated deceptions” during the case, with the first one being a “fabricated cancer claim she used as a pretence for the lunch invitation.”

“The second deception was the lethal doses of poison the accused secreted in the home cooked beef Wellingtons. The third deception was her attempts to make it seem that she also suffered death cap mushroom poisoning and the fourth deception, the sustained cover-up she embarked upon to conceal the truth,” the prosecution said.

Prosecutors added that Patterson bought, then disposed of, a dehydrator she used to cook the lunch. Investigators recovered the dehydrator and found traces of the deadly mushroom inside.

She also reset her phone to their factory settings to “delete evidence.”

BBC reports that investigators recovered deleted evidence from Patterson’s phone, and determined that she had searched the iNaturalist website for death cap mushroom sightings. Cell phone data showed that she traveled to nearby locations that contained the mushrooms before buying the dehydrator.

Further, forensic experts found images on Patterson’s phone that appeared to be the mushrooms on weight scales.

Although no motive was proven, the jury decided the prosecution provided enough evidence to convict her on three counts of murder. She was also convicted of attempted murder for poisoning her husband.

Check back for updates.

[Feature Photo via Supreme Court of Victoria]