Vic murder accused testifies over knife

A man accused of murdering his former partner after they left a Melbourne court says he can't remember how she came to be stabbed six times but she had pulled out a knife and he had to get it off her.

Craig McDermott says Fiona Warzywoda might have been stabbed by accident, or she could have stabbed herself.

He is on trial in the Supreme Court of Victoria after pleading not guilty to murdering his partner of some 18 years in Sunshine on April 16, 2014.

They had attended the Sunshine Magistrates Court earlier that day, about a month after having separated, the Supreme Court has been told.

McDermott said it happened after he tried to talk to Ms Warzywoda.

He says she came at him with a knife and he put his hand out to block it, before a struggle ensued.

"I don't know how I got the knife off of her," McDermott told the court on Tuesday.

McDermott could not recall how Ms Warzywoda suffered six stab wounds.

He did not intend to kill her, he told the court.

"I remember going for the knife until I had the knife in my hands, and then I walked off or run off, or whatever it was," McDermott said.

It was possible Ms Warzywoda was stabbed by accident, or that she stabbed herself, McDermott said.

He said he ran from the scene because he was shocked and scared.

The court has been told McDermott and Ms Warzywoda left court about midday and drove separately to a nearby shopping centre, with Ms Warzywoda going to her solicitor's office and McDermott walking around with his son.

Prosecutors allege McDermott purchased the knife before going to a cafe and watching Ms Warzywoda's car.

"When she returned to the car from the solicitor's office, he moved quickly toward her and stabbed her with a knife," crown prosecutor Brendan Kissane, QC, has told the jury.

The trial continues.