Third trial begins over WA woman's death

The lawyer for an elderly man standing trial in Perth for killing a woman more than 20 years ago claims the victim's husband cannot be ruled out as a suspect.

Ronald Leslie Pennington, 85, is facing a third trial in the WA Supreme Court, charged with the manslaughter of Cariad Anderson-Slater in July 1992.

Her remains were found in Pennington's former backyard in February 2011, and Pennington, who had moved to Tasmania, was extradited to Perth to face the charge.

In his opening address on Tuesday, prosecutor Justin Whalley said Ms Anderson-Slater was a binge drinker who often disappeared for days at a time.

He said her husband, David Slater, was concerned about her drinking and the couple, who had only lived in Perth for a couple of months, did not have many friends.

When Pennington, then aged 63, invited the couple to dinner for the second time, they had a heated debate about the monarchy, the court heard.

Afterwards, Ms Anderson-Slater and her husband argued at home about her drinking and Mr Slater ripped the phone out, Mr Whalley said.

The last time Mr Slater saw his wife alive was when she went to a neighbour's house, he said.

Ms Anderson-Slater caught a taxi to Pennington's house and then she "disappeared into thin air", Mr Whalley said.

Mr Slater and Pennington both left WA and it was not until Pennington's former property was being excavated in 2011 that Ms Anderson-Slater's skull and other remains were found.

Defence lawyer Simon Freitag said in his opening address that there was not enough evidence to convict Pennington and suggested Mr Slater could be an alternative suspect.

Mr Freitag noted Mr Slater changed his will, indicated he was a widower and began dating shortly after his wife's disappearance.

He also read an extract to the jury from a book Mr Slater wrote about his experience in which he said he needed a companion.

"I'm not going to go through this alone," he wrote.

"I was just a man alone with needs."

The re-trial continues.