The first two series released (Sheldon Creek Trilogy and Eden and Deception) both take place in South East Queensland so it seems like a good idea to write about some of the inspirations for those books.
Patrick Mayne
Patrick Mayne lived in Brisbane in mid 1800s. In Rosamond Siemon's book, The Mayne Inheritance, she presents the case that Patrick Mayne killed a sawyer, stole his money and went on to become one of the richest and most influential men in early Brisbane. Money from his family helped fund the Royal Brisbane Hospital and the University of Queensland (UQ) both of which have buildings named after the family. The family home now houses the Wesley Hospital. His trust still owns Brisbane Arcade with money going to UQ's Mayne Medical School.
If the theory is true, it's interesting to think just how different Brisbane could have been if that murder had never been committed.
Sources
https://en.wikipedia.org/wiki/The_Mayne_Inheritance
https://rbwhfoundation.com.au/wp-content/uploads/2018/03/James-Mayne.pdf
https://en.wikipedia.org/wiki/University_of_Queensland#1920s_to_1990s
https://en.wikipedia.org/wiki/Brisbane_Arcade
https://en.wikipedia.org/wiki/Moorlands,_Auchenflower
The Gatton Murders
On Boxing Day night 1898, three of the Murphy children were brutally murdered in a paddock outside of Gatton. They had been on their way to a dance but arrived to find it cancelled. They bodies were found the next day in a paddock.
Multiple mistakes by the police lead to a Royal Commission and far reaching changes to the Queensland Police Service.
Source