I worked for one of the big banks up at Kings Cross in the 70s. All these characters had bank accounts, and some were happy to have a drink and a chat.
Back when there were no mobile phones to record conversations, they were far more candid with what they said, if they trusted you.
I met Roger Rogerson, and Abe Saffron; and they were pleasant enough if you weren't a threat or a dick head.
Rogerson could tell some funny stories about policing the illegal casinos and brothels.
Never actually conversed with Neddy Smith; he was pretty quiet and oozed an aura of danger (he would have been perfect for the role in Wolf Creek).
Abe was just a pleasant guy who treated people as equals. He gave me a pair of hand made Karandonis boots for Christmas.
With Roger you could never be certain that he wouldn't just suddenly turn on you.
Working at the Cross was quite an education.
The guy they were all frightened of was a shadowy character simply known as "Big Bad". He was a Clark Kent type, who never socialised, had no police profile, and was the hit man of choice, because he did a clean job and left no clues. One of Abe's guys told me about him. He said Big Bad once did a contract job for the Mafia in California - someone "fell" under a bus. He said you would walk past him in the street and not look twice, apart from the fact that he was powerfully built, and drove an old FJ Holden. He is still an unknown character to this day.