Two white supremacists have been convicted of murdering a 42-year-old man by bludgeoning him to death with a hammer at his home in Perth almost two years ago.

Alan Taylor was killed in April 2016 at the Girrawheen house he shared with his partner Melony Jane Attwood, 37, who led the neo-Nazi group Aryan Girls.

Attwood and her 22-year-old live-in lover and Aryan Nations president Robert Edhouse, were convicted of murder by a WA Supreme Court jury on Monday after about four days of deliberating.

Corey Joshua Dymock, 21, was acquitted of murder but was found guilty of being an accessory.

A fourth person, who cannot be identified, pleaded guilty to murder and was given a reduced sentence for testifying.

As the decision was read out, a sudden outburst of violence filled the court room.

Robert Edhouse lunged at Corey Dymock, with several guards forced to pin him down while others restrained a relative in the public gallery, who tried to get to the dock.

Mr Taylor's father Robert was shaking and emotional as he left court.

"We'll never get our son back. Never," he told reporters.

"It might keep them off the street. And hopefully this will never happen to anybody else," he said.

© Nine Digital Pty Ltd 2018