Ex-Telstra technician and confessed rapist Bradley Robert Edwards, 51, is on trial in the Western Australia Supreme Court accused of murdering Sarah Spiers, 18, Ms Rimmer, 23, and Ciara Glennon, 27, in 1996 and 1997.

Kenneth Mitchell, 75, said he and his wife went to bed at their home in the semi-rural Perth suburb of Wellard on June 8, 1996 just before midnight but were awoken by woman's voice through their open window.

"We would only have been asleep for a short time and I was awoken by, I wouldn't call it squealing but certainly a very high-pitched and traumatic voice of a woman," Mr Mitchell testified on Thursday.

He said he heard her shout words to the effect of: "Leave me alone! Let me out of here!"

"It was very plain, very clear and very traumatic," he said.

Mr Mitchell said he got out of bed very quickly and it appeared the voice came from nearby scrubland.

There was then "dead silence", which he described as frightening.

He saw the reflection of lights and heard the sound of a car driving but did not see the vehicle.

Mr Mitchell said he looked around the next morning and only saw tyre tracks.

His wife Judith Mitchell, 76, testified she heard a "really agitated voice" of a woman who seemed to be arguing with someone but she could not hear the other person.

"I sat up and thought 'oh, what's going on?'" she said.

"The noise carried on for a while and then it seemed to get louder."

Ms Mitchell said she looked out a window and vaguely saw the shadow of a car and thought she saw somebody walk behind a bush.

"But I couldn't be sure on that because it was very dark," she said.

Ms Mitchell said she went back to bed because she thought it was just people having a row.

"The door slammed shut and then they just went off," she said.

She said the couple reported their experience to police after news reports of Ms Rimmer's murder calling for information.

"It was just a very weird thing."

Ian Sturcke, 71, and his wife Cheryl Sturcke, 68, were also woken by a scream, which lasted about five seconds, then was cut off.

"Dead silence," Mr Sturcke said.

"There was nothing after that.

"Never heard a scream of that magnitude in my life."

Ms Sturcke described it as "blood-curdling" and thought it was a "really serious domestic".

"Never in my life have I heard a scream like that and I never want to hear it again," she said.

Hours later, Ms Rimmer's scratched watch was found by a horserider when he was thrown from the animal.

A Telstra-issued pocket knife was also discovered by two other horseriders that day.

Weeks later, Ms Sturcke said her family would go into "automatic pilot" when they smelt something bad, putting the windows up, thinking an animal had been hit by a car.

"There's something dead in the bush," she told them.

Ms Rimmer's naked body was found under foliage 55 days after she vanished, not far from the properties.

Australian Associated Press