Why is Australia's mushroom killer back in court this week?

Erin Patterson, a 51-year-old Australian woman, was found guilty last year of murdering her husband's parents and an elderly aunt by serving them a meal containing death cap mushrooms. She was sentenced to life in prison with the possibility of parole after 33 years. However, she is now appealing her conviction, arguing that there were several errors during the trial, including a catastrophic hotel mix-up that led to jurors staying at the same hotel as prosecutors and a key witness.

Patterson's lawyers claim that this error compromised the integrity of the trial and may have influenced the jury's verdict. They also argue that some evidence presented in court was too speculative and that crucial evidence was wrongfully excluded.

The prosecution, on the other hand, is appealing against Patterson's sentence, arguing that a 33-year parole period is "manifestly inadequate". They claim that Patterson should be sentenced to life without possibility of parole due to the severity of her crimes. The Court of Appeal in Melbourne has reserved its decisions, and it will likely take weeks or months before the outcome of both appeals is known.

Patterson's victims include her husband's parents, Don and Gail Patterson, both 70, and Gail's sister Heather Wilkinson, 66, who all died after what prosecutors called "shocking illnesses" as a result of the poisoning. The only surviving guest, Heather's husband Ian Wilkinson, has never fully recovered from his ordeal.

The case centers on a July 2023 lunch at Patterson's home in Leongatha, Victoria, where she served beef Wellington containing poisonous death-cap mushrooms. Patterson's estranged husband Simon Patterson was meant to attend the deadly lunch but cancelled at the last minute, citing his belief that his wife had been trying to poison him for years.

The outcome of both appeals will determine whether Patterson will be able to challenge her conviction and sentence in court.