SYDNEY (Reuters) -An Australian woman accused of murder engaged in a calculated deception to kill three elderly relatives of her estranged husband with a meal she allegedly laced with toxic mushrooms, a court heard on Monday, as closing arguments in the trial began. Erin Patterson is 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, in July 2023. The prosecution accuses her of foraging for poisonous death cap mushrooms, drying them and knowingly serving them in individual portions of Beef Wellington at her home in Leongatha, a town of about 6,000 people some 135 km (84 miles) from Melbourne.