Triple-murderer Erin Patterson to learn her appeal fate today

Erin Patterson will today learn whether she has won an appeal against her convictions for murdering three lunch guests and trying to kill a fourth with poisonous mushrooms in 2023.

If the Court of Appeal quashes her convictions, it could either order a retrial or acquit her of the charges.

The court will also hand down a decision on a prosecution bid to keep Patterson behind bars for the rest of her life.

Triple-murderer Erin Patterson will learn within hours whether she has won her appeal against her convictions.

Patterson is serving three life sentences with a non-parole period of 33 years after a jury found her guilty of murdering her parents-in-laws Don and Gail Patterson, along with Gail's sister, Heather Wilkinson, in 2023.

The victims had been invited to lunch at Patterson's Leongatha home, in Victoria's south-east, where she served them death cap mushrooms inside beef Wellington.

Patterson, 52, was also found guilty of the attempted murder of Mrs Wilkinson's husband, Korumburra church pastor Ian Wilkinson, who survived after falling gravely ill from the poisoning.

Patterson lodged an appeal against the jury's verdicts, claiming there was a substantial miscarriage of justice during her trial, which was held in the regional town of Morwell in 2025.

Patterson's lawyers told a two-day appeal hearing in August there had been a "catastrophic" accommodation bungle during the deliberations over the verdicts, which saw the jury staying at the same hotel as the main police witness for the prosecution, as well as two members of the prosecution team.

The defence made lengthy submissions about the risk of the jury being influenced by any direct and indirect contact with the parties, even as simple as a jury member seeing one of the others through a hotel window.

It also argued that prosecutor Nanette Roger SC's cross-examination of Patterson was "unfair and oppressive".

Patterson's lawyers told the court the five-day questioning included, at times, terse exchanges which posed a risk of creating improper inferences in the jury members' minds.

They also accused Dr Rogers of changing the prosecution case during her closing addressing by implying there was a motive for the murders after telling the jury there was no evidence of a motive when she was opening the case.

When handing down Patterson's life sentence, Justice Christopher Beale set a 33-year non-parole period.

That means Patterson could be released back into the community when she's in her early 80s.

The prosecution's appeal against that minimum term focused on the severity of Patterson's crimes and the conditions she would face in jail.

The team argued that a life sentence without parole was the only option given the number of Patterson's victims, the amount of planning that went into the deadly lunch, the continuation of the offending by not revealing the poisoning to medical staff when there was a chance to treat the victims, and a lack of remorse displayed by Patterson.

The prosecution also argued Justice Beale should not have made an allowance for Patterson facing years in protective custody because of her notoriety.

The appeal court heard Patterson had access to a library, recreation centre, exercise yard and treadmill, had regular video calls with her children and engaged in hobbies such as crocheting.

Despite already hearing the appeal arguments, Court of Appeal judges Lesley Taylor, Stephen McLeish and Peter Kidd must first rule whether Patterson's case has met the requirements to be granted leave to appeal.

That means there are four possible outcomes for Patterson's appeal:

If a retrial is ordered or the court acquits Patterson, the prosecution's appeal against the sentence is no longer relevant.

If Patterson loses her appeal, the judges will then turn to the prosecution's appeal.

If that appeal is dismissed, the original sentence of life imprisonment with a minimum term of 33 years set by Justice Beale remains in place.

If the appeal is upheld, the Court of Appeal will announce Patterson's new sentence.

Due to the large media and public interest in the case, the decision will be handed down in Court 1 of the Victorian Supreme Court, not in the usual Court of Appeal building.

Patterson is not expected to attend today's hearing in person.