The twin daughters of slain Pakenham woman Kylie Blackwood have described the distress and loss they continue to feel almost six years after her death, and the fact that she will not be at their weddings or be there for her grandchildren.

Key points: Ms Blackwood's killer, Scott Alan Murdoch, is facing a plea hearing in the Supreme Court of Victoria

Ms Blackwood's killer, Scott Alan Murdoch, is facing a plea hearing in the Supreme Court of Victoria Mia and Holly Blackwood, both 17, described the trauma of finding their mother in their home when they were 11

Mia and Holly Blackwood, both 17, described the trauma of finding their mother in their home when they were 11 The court was told Murdoch showed "extremely cold behaviour" in the aftermath of the killing

Ms Blackwood, 42, was stabbed multiple times at her Pakenham home in Melbourne's south-east on August 1, 2013.

Her killer, Scott Alan Murdoch, is before the Supreme Court of Victoria for a plea hearing after pleading guilty to murder.

Mia and Holly Blackwood were 11 when they came home from school and found their mother, after she had failed to collect them.

"Images I will never be able to stop seeing, of her in agony, broke my heart in a million pieces," Mia Blackwood, 17, said via a victim impact statement describing the animosity she felt towards the "heartless killer".

"It hurts so deeply. It's unfair and it's heartbreaking."

Holly Blackwood, also 17, spoke of the "most frightening and confronting" scene on that day.

"You have taken away a mother and daughter bond that no-one can replace," she told Murdoch via a victim impact statement read to the court.

"After doing what you did … how can you call yourself a human being?"

"I hope you suffer and get what's coming to you," she said in the statement.

Both daughters spoke of their futures without their mother — in particular their wedding days and the birth of children — in detailing their loss.

Fourteen victim impact statements to be submitted

Their older brother, Chase Blackwood, told the court he was a "broken person", detailing problems he has had with relationships since his mother's death.

In his victim impact statement also read in court, he described getting home from school that day to see police tape and his father in tears.

He urged Justice Jane Dixon to "bring justice to my family please".

Via a statement, their father, Peter Blackwood, spoke of the "incomprehensible" death of his children's "beautiful, doting mother" in this "despicable crime".

"No child should go through this," he said.

The children and Mr Blackwood were not in court.

Murdoch has kept his head down through most of the hearing.

A total of 14 victim impact statements are to be submitted to the court.

Scott Murdoch covered his face as he was led from a prison van into the Supreme Court building for the hearing. ( AAP: David Crosling )

Court told of 'savagery' in earlier attack on 73yo woman

The pre-sentencing hearing is also looking at another crime Murdoch committed less than three months before he killed Ms Blackwood.

Ilona Prohaska received "life-threatening injuries" when Murdoch attacked her in her Endeavour Hills home in May 2013.

She was 73 years old at the time.

Murdoch has pleaded guilty to the murder of Ms Blackwood and also intentionally causing serious injury to Ms Prohaska.

The court was told Murdoch rang the doorbell of Ms Prohaska's house, and had a knife in his hand when she answered.

He forced her down into the basement where he used a knife and a hammer to inflict deep wounds into her neck on the left and right sides.

Prosecutor Nicholas Papas referred to the "savagery of the attack" on Ms Prohaska.

"She was able to drag herself up those stairs in quite a feat of survival," he said.

Once upstairs she found her medical emergency device — which Murdoch had thrown aside during the attack — and alerted the authorities.

The court was told Ms Prohaska had become socially isolated.

She could no longer tolerate the sound of the church organ because of damage to her ear from the attack, the court heard.

She experienced constant pain along the left side of her body.

She was listening by videolink from a remote location, as her victim impact statement was read to the court.

Initially her son was accused of the attack.

"I saw the face of my attacker and it was not my son," she said.

Prosecutors argue 'disturbing pattern of behaviour' justifies life jail term

The court was told Johnny Prohaska died not long after the attack, and Ms Prohaska had only been able to see him twice between the attack and his death.

She wanted the court to clear his name of the attack.

The court has heard of Murdoch's "extremely cold behaviour" in the wake of the attacks.

In both cases, Murdoch had stolen cash and bankcards and had attended nearby bank ATMs to withdraw money.

After stabbing and robbing Ms Prohaska he attended his regular parole check-in.

Prosecutors are seeking a life prison term for Murdoch and have asked Justice Dixon to consider imposing a maximum term only and not set a minimum or non-parole period.

Mr Papas pointed to Murdoch's past crimes, including a September 2006 attack in which he stabbed a woman in the neck after she refused to have sex with him.

He said there was a "chilling similarity" to these crimes and a "disturbing pattern of behaviour".

Murdoch's lawyers will respond at a hearing set down for next week.