Alan McIntosh used wire to strangle drug dealer Diana Matthews, self-confessed murderer tells court
A self-confessed murderer has told the Supreme Court she saw a man use a piece of wire to strangle a drug dealer as she drove along a road in Perth's southern suburbs.
Rebecca Hall was giving evidence at the trial of Alan McIntosh, who is accused of murdering 46-year-old Diana Matthews.
Ms Matthews' body was found in a pond at the Rockingham Memorial Park in April 2011.
The court has been told Hall, a mother of four, pleaded guilty to a charge of murder in February, and last week became the first person in Western Australia not to receive a life jail sentence for the offence.
The jury has been told she is a crucial witness in McIntosh's trial with his barrister Linda Black saying Hall "cut a deal" and had been given a "lenient" sentence in return for testifying against him.
Ms Black said her client maintained it was Hall who strangled Ms Matthews and who put her body in the pond.
However today Hall testified that she saw McIntosh strangling Ms Matthews in the car.
"Alan was sitting directly behind Di and he had a wire or something around her neck and was pulling it tight," she said.
"She had her hands ... trying to pull it out. She was groaning.
"I'm pretty sure he was yelling at her something about it being her fault because she should have stopped selling."
Hall said it then looked like Ms Matthews was dead and she drove down a dirt road and stopped the car in a big, open area and got out.
"I had a smoke. Alan told me to come around and give me a hand to get her out of the car," she said.
"He grabbed her by the top half, I grabbed her ankles and took her out of the car.
"We placed her on the dirt and then ended up picking her up again and putting her in the water."
Hall denied she was the one who attacked Ms Matthews and maintained it was McIntosh's suggestion to rob her of the drugs and cash she was carrying.
She also said she had decided to "voluntarily go to police two years later because it was eating away at me. I had to say what happened".
Hall said she was not told exactly what sentence she would receive if she pleaded guilty to her part in the murder, but testified it was explained to her by her lawyers she would receive a reduced sentence if she gave evidence at McIntosh's trial.
Hall will continue her evidence tomorrow.