A woman found her sister with "her head caved in" hours after a neighbour heard an altercation and "a whack like a baseball bat hitting a skull", the trial of a man charged with three cold-case murders has been told.
Mildura man Steven Leslie Hainsworth, 49, is on trial in the South Australian Supreme Court for the murders of Phyllis Harrison, 71, at Elizabeth South in 1998, Beverley Hanley, 64, at Elizabeth North in 2010 and Stephen Newton, 55, at Mt Gambier in 2011.
The court on Monday began hearing evidence about the death of Ms Hanley, who was Hainsworth's aunt.
It was told her body was found in her Elizabeth North home on October 6, 2011, along with a cricket bat covered in blood near her body and bloodied footprints throughout the house.
Leonard D'Agostino, 85, who lived adjacent to Mrs Hanley's rear yard, said he was sitting at a table outside the rear of his home when he heard an altercation at the rear of his neighbour's home about 10.30am.
He told court Ms Hanley said, "'I saw you jump my fence, what do you want?'."
"There was an argument, muffled. It got a bit nasty. It's hard to describe. It was a whack, a thud or a hit, or something. Imagine a baseball bat being struck (on a) skull."
Asked by Director of Public Prosecutions Martin Hinton KC if he heard any other voices, Mr D'Agostino said: "I don't think I heard him talk."
"You say 'him'. What makes you say 'him'?" Mr Hinton asked.
"She knew him," he said.
"It's a terrifying thing. To hear somebody getting whacked over the head with a baseball bat. I assume it was that."
Mr D'Agostino said he "got a bit agitated".
"I said 'Leonard, you better do something'. I went around to her house ... it was dead quiet."
Ms Hanley's sister Cheryl McGee told the court she arrived at Ms Hanley's home mid-afternoon to drop off homemade tomato sauce.
She knocked on the front door and when there was no answer, she went into the house and started shouting "where are you?" because Ms Hanley had poor hearing.
Ms McGee checked her sister's bedroom which was "a mess ... everything was everywhere".
She continued searching the home and "I looked down the hallway and I could see Bev's feet".
"I ran towards her feet and seen her laying there," she said.
She said half of her sister's body was outside, blocking the screen door, which was half open.
"There was a heap of blood and her head was all caved in," she said.
Ms McGee became distressed while giving evidence and the court briefly adjourned.
She told the court she rang triple-zero on a hands-free phone and went back to her sister.
"The lady on the phone, she wanted me to do CPR," she said.
She said she "sort of" did CPR, but "she was just so cold… she was just laying there, all blue."
Ms McGee said a neighbour named Ron came running into the home because "he must've heard me screaming".
"The poor old man, he was that frail, he was that upset, he just tried to tell me it was all going to be OK," she said.
Ms McGee said her sister had kept a cricket bat next to her front door "for protection".
Prosecutors previously told the court Hainsworth lived within walking distance of his aunt's home.
The judge-alone trial continues before Justice Adam Kimber.
