A jealous killer has been sentenced to life in prison for the stabbing murder of his childhood friend after he discovered his victim was in a relationship with his ex-girlfriend.

Key points: Tan Van Vo stabbed Jason Tran to death in his ex-girlfriend's Alexander Heights house

Tan Van Vo stabbed Jason Tran to death in his ex-girlfriend's Alexander Heights house The judge said the murder was "particularly cowardly" and motivated by jealousy

The judge said the murder was "particularly cowardly" and motivated by jealousy With his sentence backdated, Vo will not become eligible for parole until 2034

Perth man Tan Van Vo, 29, stabbed Jason Tran as he laid in bed in the early hours of the morning in Vo's former partner's house in Alexander Heights in November 2017.

Wearing white latex gloves and armed with a large hunting knife, Vo rode his bicycle from Girrawheen to the house about 1:30am and climbed through a bedroom window.

His former partner, Vanessa Heung, watched as Vo jumped onto her bed and stabbed Mr Tran, 27, a number of times.

Ms Heung managed to pull Vo out of the room, but Mr Tran was already bleeding heavily with deep stab wounds to his neck, thigh and back.

The knife had severed his femoral artery and vein and he died in hospital later that morning.

Knife hidden in garage after meth-fuelled murder

After fleeing the scene, Vo went to a friend's house in Marangaroo about 2:00am and after they ate and talked for some time, he hid the knife in his friend's garage.

The knife was discovered by police and Vo was arrested at his mother's house in Girrawheen later that day.

The Supreme Court heard that when interviewed by police Vo initially denied any knowledge of the incident, but later conceded he had gone to Ms Heung's house wanting to "stab or bash" Mr Tran.

The Supreme Court heard the murder was motivated purely by Vo's anger and jealousy. ( ABC News: Briana Shepherd )

He told police he had been angry because Mr Tran had "chatted up my girl".

Appearing in court for sentencing, Vo looked down through most of the proceedings and at times trembled slightly.

Defence lawyer Seamus Rafferty said while his client did not have a diagnosed mental illness, his behaviour at the time had been "bizarre", likely as a result of his use of methamphetamine.

He said Vo now felt "deep, deep remorse" and was taking measures to address his drug addiction.

Among character references provided for Vo was one from Ms Heung, who Justice Stephen Hall said had visited her ex-boyfriend in prison and had forgiven him for the crime, which she attributed to his drug use.

'Cowardly' killing leaves victim's family devastated

Sentencing Vo, Justice Hall described the murder as "particularly cowardly" and "violent", and said it had taken place for no reason other than the killer's "anger" and "jealousy".

Justice Stephen Hall sentenced Vo to life in prison with a minimum term of 17 years. ( Supplied )

He also made reference to a victim impact statement provided by Jason Tran's sister, which he said detailed the deep distress their family had suffered and the lasting impact it had.

The statement described how Mr Tran's mother had trouble sleeping and eating, had suffered weight loss and no longer went out as "everywhere she goes reminds her of Jason".

It also detailed that Mr Tran's young nephew still asks to see him.

Vo will have to serve a minimum of 17 years behind bars before he is eligible for parole.

With the sentence backdated, his earliest release date will be in 2034.