At 10.42am, someone had dialled triple zero, but the call did not connect.

Police officers discovered Ms Michelutti's lifeless body in her bedroom covered in bed clothes. She had been stabbed once in the abdomen.

Gavin De Beyer, 51, her husband of 15 years and partner of several more years, is now on trial for her murder.

Mr De Beyer has pleaded not guilty and claims Ms Michelutti - the mother of his children - stabbed herself.

In his opening address to the NSW Supreme Court on Wednesday, Crown Prosecutor Ken McKay said the couple were the only people who witnessed the incident but a body of circumstantial evidence pointed to Mr De Beyer as the stabber.

He told the jury the couple's relationship had been unhappy for some period.

He said their daughter Kalyra??? Michelutti, who was 19 at the time, would tell the court she spoke to her mother by phone twice at about 10am on the morning of February 1, 2016.

She will say her mother was "acting normally" but she could hear her father "screaming in the background".

CCTV footage at Woolworths Riverwood shows Mr De Beyer at the supermarket between 10.18 and 10.21am. He is then seen again at 10.53am on CCTV cameras outside the Morris Iemma community centre about 1 kilometre from the couple's Kentucky Street home.

Mr McKay said the Crown case is that Mr De Beyer murdered Ms Michelutti between 10.21 and 10.53am.

A family member, who cannot be identified for legal reasons, will give evidence that he saw Mr De Beyer briefly before Mr De Beyer left the house and Mr De Beyer said he was going to collect his car. He did not mention that Ms Michelutti was lying in her bedroom with a stab wound.

About midday Mr De Beyer went to Campsie police station and said his wife was dead.

Mr De Beyer's defence barrister Angus Webb said the couple had started dating in their teens and married many years into their relationship.

Mr Webb said there is no dispute that police were called to the house on some occasions over the years.

"It was a relationship that had its ups and downs," he said.

He said there was no evidence to show who used the mobile phone to dial triple zero and urged the jury to "keep an open mind".

A long-time neighbour and close friend of Ms Michelutti, Lissa Elzein said police were called to the house "quite often" in the year leading up to her death.

"The police were always coming...sometimes once a week. The police would come and then they would leave," she said.

She said she regularly heard arguments between the pair and their voices were so loud she could hear them from inside her house two doors down.

She said on one occasion she saw the pair walking along the footpath - Mr De Beyer in front and Ms Michelutti behind.

"Gavin said, 'C'mon Sharon, you dog, woolf woolf, hurry up'," Ms Elzein said.

She said in 2011 Ms Michelutti was taken to hospital by ambulance following an overdose of painkillers.

Under cross-examination she said Ms Michelutti had used marijuana for a great deal of her adult life and she and Mr De Beyer were frequent attendees at the local pub.

She said in 2015 the couple were using ice, or methamphetamine, and money and drugs became a "central issue" in the relationship.

She agreed Ms Michelutti once told her she "didn't want to live anymore" and "wanted to be with her father" Angelo Michelutti, who's death profoundly affected her.

"Sharon just really missed the love of her dad," Ms Elzein said.

The trial before Justice Peter Hidden continues.