A tragic case of jealousy turned fatal when a Samoan father-of-five brutally murdered his wife, driven by unfounded suspicions of infidelity involving his brother.

Rimoni Muliaga, aged 44, savagely attacked his 37-year-old wife, Lise Muliaga, with a large kitchen knife in a violent outburst on September 18, 2023. The incident occurred in the backyard of his brother’s home in Melton South, a suburb on the outskirts of Melbourne, shortly after the family had relocated from New Zealand.

Three of the couple’s young children, aged 12, seven, and five, were unfortunate witnesses to the horrific event and its aftermath, leaving them traumatized.

In a strong condemnation delivered on Wednesday, Justice James Gorton of the Supreme Court of Victoria addressed Muliaga’s actions.

“You stabbed your wife, Lise, multiple times with a kitchen knife. You did so in front of your children in the backyard of your brother’s house,” Justice Gorton stated, emphasizing the gravity of the crime.

“You attacked her based on a mistaken belief that she was having an affair with your brother,” he added, highlighting the tragic consequences of Muliaga’s misguided jealousy.

The judge described the killing as ‘an act of the most serious domestic violence against an innocent and unarmed woman’ that ‘warrants serious condemnation’.

Muliaga had argued with his wife that morning after accusing her of the affair – a suspicion he had harboured for some time despite it being entirely unwarranted. 

Rimoni Muliaga, his wife Lise and their children in happier days 

After she returned from a walk, the row escalated in the bungalow where three of the children were present.

The court heard Muliaga attacked his wife with the knife, stabbing her four times – twice to the right shoulder, once to the left upper chest and once to the left breast.

The fatal wound was a 9.5cm 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.

Mrs Muliaga had fought for her life and suffered defensive knife cuts to her arms as she desperately tried to fend him off.

‘It was a frightening and violent death,’ Justice Gorton said.

The court heard one of the couple’s young daughters ran screaming to the main house. 

When family members rushed to the backyard, they found Mrs Muliaga sitting on the ground with the knife still sticking out of her shoulder, bleeding heavily.

Muliaga was seen standing over her.

Rimoni Muliaga butchered his wife Lise in a jealous frenzy 

His sister-in-law screamed at him asking what he was doing.

The killer fled up the street but later insisted: ‘Lise and (his brother) were sleeping together.’

Muliaga’s brother called triple zero and performed CPR, but despite briefly regaining a heartbeat, Mrs Muliaga was declared dead at 2.33pm.

Muliaga was arrested nearby with blood still on his hands. 

The court heard he repeatedly asked police for his ‘mental health medication’ and said he hadn’t taken it since the previous day.

Justice Gorton said Muliaga appeared genuinely shocked and distressed when told his wife had died, even asking to call her.

A jury found Muliaga guilty of murder in December after a trial in which he admitted the stabbing but contested his intention.

Justice Gorton sentenced Muliaga on the basis that he stabbed his wife with the intention of ‘causing really serious injury’, without caring whether she lived or died. 

Rimoni Muliaga enters the Supreme Court of Victoria in February 

The judge noted the attack was spontaneous, not premeditated, but entirely unprovoked. 

The fact that three children witnessed their mother’s violent death was an aggravating factor that heightened the objective seriousness of the crime, Justice Gorton said.

The court heard Muliaga was born in Samoa in 1981, one of nine children, and had a difficult upbringing involving physical abuse.

The court heard Muliaga had a low IQ of just 61, placing him in the bottom 0.5 per cent of the population and meeting the threshold for intellectual disability, along with impaired executive functioning and rigid thinking.

He had a history of mental health issues, including depression with psychotic features and a prior diagnosis of schizophrenia in New Zealand. 

A forensic psychiatrist who assessed Muliaga concluded he suffered from a major depressive disorder rather than schizophrenia.

While the court found the condition reduced his moral culpability, Justice Gorton stressed it did not excuse the crime. 

Rimoni Muliaga enters the court during his murder trial 

Muliaga knew what he was doing was wrong, Justice Gorton said. 

The court heard Muliaga had previously been violent towards Lise, including one incident where his brother found him on top of her and another where his sister-in-law saw him with his hand around her neck.

Their children, now coping with the support of family, submitted victim impact statements declaring they faced life without their mother and the trauma of knowing their father killed her.

Muliaga, who is not an Australian citizen, is likely to be deported upon release.

Justice Gorton sentenced Muliaga to 24 years in jail with a non-parole period of 18 years and six months. 

He has already served 919 days in pre-sentence detention.