Erin Patterson's next steps as the death cap killer faces a long prison stint

Patterson will have the chance to appeal the court's decision after Justice Christopher Beale delivers a sentence.

Associate Professor Andrew Hemming, a criminal law expert at the University of Southern Queensland, said the 50-year-old will likely be an elderly woman by the time she's released from prison.

"Murder is a level one imprisonment offence, so potentially life imprisonment. But the standard period [for one murder conviction] is 25 years," he said.

Patterson was found guilty of three counts of murder and one count of attempted murder at Latrobe Valley Magistrates' Court on July 7 in the trial's eleventh week.

READ MORE: Reaction to the mushroom killer's verdict and behind the Erin Patterson story

The jury heard from more than 50 witnesses connected to Patterson and a fatal lunch she cooked in July 2023 at her Leongatha home that claimed the lives of Heather Wilkinson, Gail and Don Patterson.

Heather's husband, Ian Wilkinson, survived the beef Wellington laced with death cap mushrooms after undergoing a successful liver transplant.

The length of Patterson's time in prison will be determined by Justice Christopher Beale in a sentencing hearing.

The prosecution and the defence will make suggestions as to the appropriate level of sentence, Associate Professor Hemming said.

"Section three of the Victorian Crimes Act spells out the punishment for murder. The standard period is 25 years," he said.

"We're not talking about a standard sentence here because three people have been murdered, and there was one attempted murder."

A murderer may be sentenced to 30 years in prison if the victim was a custodial officer or an emergency worker on duty.

Associate Professor Hemming said that multiple murder cases were "normally treated in the same vein" as killing an emergency worker on duty, attracting a longer sentence.

If Patterson decides to contest her verdict or sentence, she may take her case to the Court of Appeal.

The court has a panel of three judges, who would assess whether Patterson's trial was "a substantial miscarriage of justice".

"This is a high bar," Associate Professor Hemming said.

"They've got to show that the verdict is unsafe and unsound and should be quashed," he said.

"That's no easy task, given the centrality of the jury in our criminal justice system."

If Patterson has a failed bid at the Court of Appeals, she could seek leave to go to the High Court of Australia, Associate Professor Hemming said.

"Now, to give an indication of how hard that is, only about seven per cent of leave applications to the High Court are taken," he said.

If all appeals have failed, and Patterson still feels that justice was denied, she may make an application to the Attorney General for judicial review.

But to get a judicial review, her lawyers must be able to present "fresh and compelling" evidence that was not available during her trial.

It's "the last gasp," the criminal law expert said.