How does a person go from a once highly decorated NSW police detective to luring, (at the age of 73) a 20-year-old to a Sydney storage unit, murdering him and then dumping the body at sea the next day in waters off Crunulla?

This is the question that author and former police detective himself Duncan McNab sets out to answer in what is his second book on this country’s most infamous and crooked former cop. The answer is delivered across 30 chapters in this book but may be summarised in just one word – ‘incrementally’.

In Australia’s long, inglorious history of bent coppers – going right back to the country’s very first constable James Smith, dismissed by Governor Arthur Phillip for larceny – there has been none more tarnished and synonymous with crime then Roger ‘The Dodger’ Rogerson.

In a notorious career, which included associations with some of Australia’s worst criminals (he famously ventured on speaking tours with professional stand-over man and alleged author Chopper Read), extrajudicial killings, being implicated in various murders and disappearances; countless allegations of threatening behaviour, bribery and drug dealing; and convictions for perverting the course of justice and perjury, he was dismissed from the police force in 1986 and jailed twice.

He is now 76 years of age and began serving a ‘life’ sentence in Sydney’s Long Bay jail in September of last year for the 2014 pre-meditated murder of twenty year old Jamie Gao, that took place inside Rent-A-Space storage shed 803 housed within a deserted industrial estate in the Sydney south-western suburb of Padstow.

Channel 7 has a telemovie co-starring Toni Collette planned for release on the whole sorry, sordid tale later this year.