WA man killed step-mum in frenzied attack

A teenager on drugs was so enraged that his stepmother was kicking him out of the house that he fatally stabbed her in a frenzied attack, a Perth court has heard.

Catalin Alin Borbil was aged 19 when he murdered Sally Kaur, 57, in her Koondoola home on December 5, 2013.

The Supreme Court of Western Australia heard on Monday that the victim had thrown Borbil out and that he had consumed methylamphetamine before his father told him to return home the next day.

But when he arrived, Borbil found his bags packed and fought with his stepmother.

"Dad doesn't want you here, you've done enough trouble," she told him.

"You don't belong in this house."

When Ms Kaur accidentally cut Borbil with a knife, he stabbed her 15 times in the chest, neck and stomach, leaving her in a pool of blood, the court heard.

Borbil then ransacked the house and stole a Rolex watch to help pay his drug debt of up to $35,000.

Defence lawyer Natasha Stewart said Borbil felt like his stepmother had no right to throw him out and, although he did not hate her, resented her.

Ms Stewart said there had been a build-up of tension before Borbil exploded.

"It was in no way planned," she said.

"He responded after being cut.

"He did not start physically attacking until after that point."

Ms Stewart said Borbil had never denied his actions, had demonstrated remorse by pleading guilty and still had his whole life ahead of him.

The court heard Borbil was born in Romania and had a rough childhood that included malnourishment and domestic violence, and he could not read or write.

The prosecutor submitted that Borbil had no victim empathy and his personal circumstances had little weight given the seriousness of the crime.

Borbil will be sentenced next week.