Justice Gorton stated that Muliaga stabbed his wife because he mistakenly believed she was having an affair with his brother. Muliaga argued with his wife that morning after accusing her of the affair, a suspicion he had nurtured for some time despite it being baseless, according to the court. The family had emigrated from New Zealand to Australia just weeks before the murder.
According to Daily Mirror - News, Rimoni Muliaga described his wife and brother as sleeping together, though the motive or circumstances behind his baseless suspicion remain unclear. Muliaga stabbed his wife four times: twice to the right shoulder, once to the left upper chest, and once to the left breast. 5cm stab to the upper chest that cut through two ribs, transected two major blood vessels, caused massive blood loss, perforated the chest cavity, and damaged a lung.
Lise Muliaga suffered defensive knife cuts to her arms as she tried to fend off the attack. Three of their children, aged 12, seven, and five, witnessed the assault and its aftermath. One of the couple's young daughters ran screaming to the main house after the attack.
Lise and (his brother) were sleeping together.
The identities or current conditions of the three children who witnessed the attack have not been made public. Family members discovered Lise Muliaga sitting on the ground with the knife still protruding from her shoulder, bleeding profusely. Muliaga was seen standing over his wife after the stabbing, and his sister-in-law screamed at him asking what he was doing.
Muliaga's brother called triple zero and performed CPR on Lise Muliaga. Muliaga fled up the street after the attack. Lise Muliaga briefly regained a heartbeat but was declared dead at 2:33 PM.
Muliaga was arrested.