The Supreme Court heard from 20 family members who wept as they told Justice Jane Dixon how they struggled to get the image of their "Kenny", laying motionless and tied up on the floor of his Springbank bedroom, out of their minds.

Kenneth "Kenny" Handford was found lying face up, with his hands bound by his dressing gown cord and legs tied to his bed on the morning of September 15, his 90th birthday.

He had been stabbed 13 times in the back, with a sock which is believed to have been used as a gag laying beside him.

Prosecutor Justin Lewis told the Supreme Court sitting in Ballarat on Wednesday the accused, 40-year-old Adam Lucas Williamson and 29-year-old Jonathon Jeffrey Cooper, kicked open the back door of Mr Handford's home on Bungaree-Barkstead Road in the early hours of September 14, before Cooper stabbed him with a double-edged knife and they both rummaged through his belongings.

They had been overheard planning the home invasion a day earlier, believing Mr Handford (who was known to carry large amounts of cash with him) may have $20,000 in cash hidden in his bedroom.

The court heard Williamson knew this because he had worked alongside Mr Handford at the Springbank potato farm for a number of years, and was believed to have been taking money from him during that time. 

The court also heard Williamson disliked Mr Handford.

Williamson and Cooper left Mr Handford's bedroom on the morning of September 14 with his WWII medals, jewellery and $3900 in cash.

The court then heard Mr Handford's pace maker showed he spent four hours and 38 minutes lying on the floor until he succumbed to his injuries.

Both men confessed to the murder to associates, with Cooper telling a friend Mr Handford recognised Williamson during the home invasion.

"You're killing me Adam (words of Mr Handford)," Cooper told his friend, the court heard.

But after a media release was issued asking for public assistance, Cooper, his friend and Williamson met up.

The court heard Williamson received a phone call, but failed to hang up.

The men were then overheard by police on the monitored call talking about the media release and car used on the night of the murder.

Two days later Williamson, of Sebastopol, and Cooper, of Wendouree, were arrested.

On Wednesday they both pleaded guilty to one count each of murder, aggravated burglary and theft.

Hearing from family members in court, Mr Handford's grandson revealed he had known Williamson for more than a decade.

"The fact he knew Ken, my grandfather, fills me with rage," he said.

"Now I've lost my faith in humanity.

"My grandfather was an irreplaceable friend. He did not deserve to go the way he did."

Mr Handford's only remaining sibling, Ron Handford, told the court he struggled to get the details of the murder off his mind.

"Nothing will change the fact my brother Kenny was murdered in horrific circumstances," his statement read.

"I can't get the picture out of my head."

Mr Handford's kindness was repeated in many statements, with his daughter telling the court her father was loved by many.

"He was so loved without an enemy in the world," the court heard.

She said she often spoke about death with her father, with his words now haunting her.

"He would tell me 'I'm not afraid of dying ... it's how I'm going to die that scares me’."

Mr Handford retired in 1980, but continued to work as a farm hand at the Bungaree-Barkstead Road farm after moving to Springbank in 1996.

Born in Ballarat, he served in the Royal Australian Air Force during WWII in New Guinea.

Cooper's lawyer, Jason Gullaci, told the court his client was affected by listening to the family speak in court.

During his submissions, he said it was conceded Cooper's offending was "despicable and cowardly".

"He is appalled and ashamed of how he conducted himself on the night," Mr Gullaci told the court.

As for the offending on the night, he said Cooper had never met Mr Handford before, but had been motivated to rob him by the idea of making easy money.

Despite being under the influence of ice and not having slept for almost three days, Mr Gullaci said Cooper entered the property with no intention to assault or murder Mr Handford.

"The murder should be viewed as spontaneous," he said.

Describing Cooper's childhood as disturbed, Mr Gullaci said his client had a long history with anger.

But having spent 407 days in custody, he said Cooper has now had an opportunity to re-live his actions.

He urged the magistrate to take into account Cooper's remorse and guilty plea, where he implicated himself as the sole stabber, and to consider giving him a non-parole period rather than life in prison.

Williamson’s lawyers will make submissions tomorrow when the plea hearing continues from 10.30am.