Erin Patterson did not react and stared at a jury as they delivered her fate.

The 50-year-old mother blinked but appeared emotionless as four guilty verdicts were read out by the jury's foreperson to a full court-room of onlookers.

"Guilty," the jury's foreperson repeated four times to each count: first to Ian Wilkinson's attempted murder, then his wife Heather's murder, followed by the murders of Gail and Don Patterson.

Within hours of the verdict, the Supreme Court released dozens of pieces of evidence that helped prosecutors secure the conviction.

This included photos showing remnants of beef Wellington leftovers as they were tested by toxicologists, after police found them inside a bin at Patterson's home.

A video of Erin Patterson discharging herself from Leongatha Hospital, minutes after she had arrived, was also released and showed her speaking to hospital staff at the entrance.

Images of Patterson at Leongatha Hospital, after she took herself there, revealed a pink phone police say they never recovered.

Prosecutors said this was Patterson's primary phone in 2023 and claimed she had used it to find death cap mushrooms online.

Ian Wilkinson outside court. – AAP

Photos of yellow mushrooms on scales were released, along with footage of Patterson getting rid of a food dehydrator at Koonwarra tip.

The Sunbeam dehydrator, which she bought three months before the lunch, was found to contain death cap mushroom toxins.

The jury's guilty verdicts came seven days after they had been sent away to deliberate and 11 weeks into the trial in Morwell, regional Victoria.

Patterson faces a sentence of life in prison for the three murders and one attempted murder.

The families of the murder victims, who died in hospital days after eating lunch at Patterson's Leongatha home on July 29, 2023, were absent for the verdicts, as was sole lunch survivor Ian Wilkinson.

Patterson, who took the stand for eight days during her trial, claimed she had not intentionally poisoned her lunch guests with beef wellington parcels.

She claimed deaths of three members of her husband Simon's family were a terrible accident, and she may have accidentally included foraged mushrooms in the meal.

Police investigate at Erin Patterson's property. - AAP

Don and Gail Patterson, 70, and Gail's sister Heather Wilkinson, 66, all died in hospital days after eating the meal, while Heather's husband Ian Wilkinson became sick but survived. 

Prosecutors laid out an extensive circumstantial case during the trial in Morwell, regional Victoria, to prove the poisoning event was deliberate.

This included evidence from sole lunch survivor Ian Wilkinson, who said Patterson had served individual beef wellingtons to her guests on different plates to her own.

The prosecution accused Patterson of telling a series of lies to police, including that she did not forage for mushrooms in the meal and did not own a dehydrator.

She lied about it to public health investigators, who were searching to find the source of poisonous mushrooms after Patterson claimed they may be from an Asian store.

Patterson lied to doctors, nurses and toxicologists while they were trying to identify why her lunch guests were sick and save their lives at hospital.

She revealed for the first time that she enjoyed foraging for wild mushrooms when she was in the witness box, admitting she started mushrooming in 2020 during the pandemic.

"They tasted good and I didn't get sick," she told the jury about preparing and eating wild fungi for the first time.

After hearing more than two months of evidence, a jury of 14 was whittled down to 12 jurors who retired to deliberate on their verdicts one week ago, on June 30.

They returned after deliberating for seven days with a four guilty verdicts, convicting the 50-year-old woman of three murders and one attempted murder.

The courtroom fell silent as the foreperson read out four guilty verdicts.

Justice Christopher Beale thanked the jury for its service and gave members dispensation from serving on another jury for 15 years.

"You've been an exceptional jury," he said.

Patterson was driven to prison in Melbourne from Morwell on Monday evening and will return to court for a pre-sentence hearing later in 2025.

She now faces a sentence of up to life in prison and will return to the court for a pre-sentence hearing later this year.

Colin Mandy, Patterson's defence lawyer and one of Melbourne's top criminal barristers, made no comment as he left the court through a scrum of journalists.

Jessica O'Donnell, a spokesperson for Patterson’s estranged husband, Simon Patterson and his siblings, also declined to comment.

Dean Thomas, a detective with Victoria Police, thanked investigators for their work on the case.

"I think it's very important that we remember that three people have died, and we've had a person that nearly died and was seriously injured," he said in a brief statement outside the court.

"I ask that we acknowledge those people and not forget them."

The families of the victims had requested privacy and would not be making a statement, he added.

Patterson's supporter Ali Rose Prior said she was "saddened" by the verdicts.

"I didn't have any expectations, it's the justice system and it has to be what it is," she told reporters.

She confirmed Patterson had told her "see you soon" and she would visit her friend in prison. 

The key factors of the case

The lunch

Erin Patterson was charged with the murders of her mother-in-law Gail Patterson, father-in-law Donald Patterson and Gail's sister, Heather Wilkinson, along with the attempted murder of Ian Wilkinson, Heather's husband.

All were relatives of her estranged husband Simon Patterson, who declined the invitation for the July 29, 2023 lunch.

The four gathered at Erin Patterson's home in Leongatha, a town of about 6,000 people some 135 km (84 miles) southeast of Melbourne, where the mother of two served them individual Beef Wellingtons accompanied by mashed potato and green beans.

The Wellingtons were later found to contain death caps, among the world's deadliest mushrooms.

Within hours, the four fell seriously ill and were admitted to hospital. Ian Wilkinson, who spent weeks in an induced coma, was the only survivor.

The trial

The ten-week trial began on April 29 in Morwell, a former coal mining town about two hours east of Melbourne.

Overseen by Justice Christopher Beale, it generated huge interest in Australia and internationally.  Members of the public queued each morning to be able to watch proceedings from the gallery.

Public broadcaster ABC's daily podcast on the proceedings was the country's most popular for much of the trial, while streaming service Stan has commissioned a documentary on what it says is "one of the highest profile criminal cases in recent history".

Patterson will be sentenced at a later date. The charges carry a maximum life sentence.

Prosecution

The prosecution, led by Nanette Rogers, spent a month laying out its case against Erin Patterson.

Rogers told the court that the accused had foraged for the death caps, dried them and measured out a "fatal dose" on her kitchen scales before adding them to her guests' Beef Wellingtons, ensuring her own food was untainted.

It was all part of a "sinister deception", Rogers argued, saying Patterson had lied to police when asked whether she had ever foraged for mushrooms or owned a food dehydrator, which was later found in a landfill site and contained traces of death caps.

A courtroom depiction of Mushroom cook Erin Patterson during the trial. - AAP

Dozens of witnesses, including relatives and forensic, medical and mushroom experts, gave evidence for the prosecution.

Among them was Simon Patterson, who told of the couple's strained relationship in the months before the fatal lunch.

Ian Wilkinson also gave evidence, telling the court the accused had served her own meal on a different coloured plate.

Defence

Patterson's defence, led by barrister Colin Mandy, did not dispute there were death caps in the meal or that she had lied to police about key details such as foraging for mushrooms.

But Mandy told the court the deaths were a "terrible accident" and that while the accused might have had "spats and disagreements and frustrations" in her relationship with her estranged husband she had no reason to kill her lunch guests.

Patterson gave evidence in her own defence and spent eight days in the witness box including five days of cross-examination by Rogers.

She was the only witness for the defence.

Jury

Fifteen jurors were initially selected for the trial and 12 were chosen by ballot to take part in the final deliberations.

Justice Beale repeatedly instructed the jury not to conduct their own research on the case, or to discuss it outside the jury room.

One juror was dismissed in May for allegedly discussing the case with family and friends.

Jurors in Australia are not responsible for sentencing and are not allowed to speak publicly after the trial.

The jury returned a unanimous verdict, a requirement for securing a murder conviction in Victoria, the state where the case was held.