Going to play the devil's advocate, and mention drugs, in the book they trusted men are Tom Prior, BL probably not his real name new Suzanne Armstrong and lived with her before she went overseas, IJ who was the police officer , not a time that he was with Suzanne Armstrong, and left the force,
BL said in his own words I thought something was going on if I was right it was dangerous, he said it was heavy stuff ...what drugs? This is only speculation on my part was Susan Armstrong killed due to connections with organised crime and drugs and a friend Susan Bartlett ,was murdered because she came to aid to help her, was Suzanne Armstrong promised easy money from IJ or his connections or someone in law enforcement or courts like a criminal lawyer to be to be a drug mule..... again, like she did in Colombia, carrying a suitcase full of cocaine to Miami. Which she did, was it marijuana, which was big in the 70s around Griffith and parts of Melbourne that the time, which ended in a Whistleblower, Donald McKay's murder was Susan Armstrong over her head with the wrong crowd, and something went wrong.
I must watch Clint Eastwood's movie where he was a mule for the drug cartels , again very interesting scenario probably not the truth but maybe, I think with people like this , all you have to do is make one mistake ,and you will pay for it with your life.