Erin Patterson's murder convictions for the deaths by mushroom poisoning of her estranged husband's relatives has prompted fevered speculation across Australia about her motive.

The fact she had no clear motive was central to her defence team’s arguments. Patterson, who foraged wild mushrooms in her spare time and also ate the beef wellington, claimed that the event was a tragic accident.

An alleged murderer testifying as a witness in their own defence is a rare strategy and normally a last resort.