Mildura man Steven Leslie Hainsworth, 49, is on trial in the South Australian Supreme Court charged with 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.
Alan Jones told the court on Friday that he bought a property at 120 Ridley Rd, Elizabeth South in 2007. While clearing a dense hedge from the property, he came across a foldable knife with wooden handle and brass inlay.
Steven Leslie Hainsworth is accused of three murders between 1998 and 2011. (David Mariuz/AAP PHOTOS)
The property is around the corner from 34 Harvey Rd, where Hainsworth lived in March 1998, when his neighbour, Mrs Harrison, was found dead on her kitchen floor.
Mr Jones, who said he was wearing gardening gloves when he made the discovery, told the court he contacted police, who took the knife from him.
Earlier, Hainsworth's then partner Helen Organ agreed that she made a statement to police in October 1998, in which she described his movements on the morning of March 3, 1998, hours before Mrs Harrison's body was found by her 11-year-old grandson.
"I saw him knock on (Mrs Harrison's) front door. Nobody answered," she said in her statement.
"He then walked down the side of the house with (my daughter) Vanessa and came back with a tennis ball."
Giving evidence on Thursday, Mrs Harrison's granddaughter, Kylie Harrison, said Hainsworth approached her days after the alleged murder and said "one of his kids had hit a ball over the fence".
"He said that it was around 8.30 on the Monday night and said it was too late to come over, so he went over the next morning and went to the front door but there was no answer," she said.
Phyllis Harrison, Stephen Newton and Beverley Hanley were all allegedly killed by Steven Hainsworth. (Supplied by South Australia Police/AAP PHOTOS)
Ms Organ confirmed in her statement that police recorded a conversation with her and Hainsworth on March 3, 1998.
"Steve and I were interviewed by the detectives and they took Steve's shorts, a T-shirt, and his socks, jocks and boots," she said in the statement.
In other evidence, ambulance officer Renata Flaherty told the court she went to 36 Harvey Rd with her partner on March 3, 1998, responding to a report of a collapsed unconscious person.
She said she found a lady on the kitchen floor who was "obviously deceased".
"I had a hard time processing what I had just seen," she said.
"There was a lot of blood around her head. I think I was also distracted by the fact that I saw that her stockings appeared to have been taken down and I was having a really hard time with that."
Earlier this week, prosecutors alleged that Hainsworth, then aged 23, had entered Mrs Harrison's home via an unlocked door at the rear of the house about 8pm on March 2, 1998 looking for items of value.
They alleged that when he encountered Mrs Harrison in her kitchen, he stabbed and killed her.
The judge-alone trial before Justice Adam Kimber continues on Monday.
