Bernie Johnson was the chief of Western Australia's vice squad when the brothel madam was shot four times in the head with .22 calibre bullets at point blank range as she sat in her Dodge at the Royal Perth Golf Club in June 1975.

At the inquest last year, which will resume in July, the WA Coroner's Court heard from retired policeman Brian Eddy, who claimed he saw Ms Finn in the police canteen with Mr Johnson just before she was murdered.

Maxwell Healy testified he drove past the golf club on the night she was killed and saw Mr Johnson standing on the road, having recognised him from a bar they both frequented.

He also said the late WA premier Ray O'Connor, whom he'd known for many years and was police minister at the time of the murder, told him Mr Johnson had stolen a .22 rifle from the police armoury.

The court also heard from convicted horse race fixer Bob Meyers, who claimed his friend Colin Pace, then head of the fraud squad, had told him Mr Johnson shot Ms Finn with a gun stolen from the police armoury.

Another witness, Philip Hooper, claimed he saw Mr Johnson near the murder scene, moments after he saw Ms Finn's car and heard gun shots.

Mr Hooper also said he was repeatedly threatened by a gun-toting Mr Johnson over many years.

And Ms Finn's live-in lover Rose Black testified Ms Finn was going to meet a man known as "The Bear" to sort out her tax problem on the night of the murder.

Mr Meyers referred to Mr Johnson as "BJ The Bear".

Mr Johnson did not give evidence during last year's hearings because he has dementia.

Author Juliet Wills, who wrote the book Dirty Girl about the case and is close friends with Ms Finn's daughter Bridget Shewring, told AAP they had been trying to bring Mr Johnson to account for his part in the murder.

"We never will have that chance but hopefully some of those that have held onto their secrets through fear of the man will now come forward and reveal what they know," Ms Wills said.

Ms Shewring said his death came as a relief.

"Sadly he won't be able to answer the many questions I have been seeking for so long," she wrote on her Facebook page.

"I hope that people will start talking and telling me the truth, as I believe he had a lot of pull on a lot of people up until he died."

The WA Police Union has offered condolences to Mr Johnson's family.

Australian Associated Press