Writer/director David Michôd said he often relented to Ben Mendelsohn's request for additional takes of his scenes because his respect for the actor's 'wild, unpredictable' contributions. In fact, the very first scene featuring Mendolsohn's 'Pope' character took about 15 takes.
The film is loosely based on the Melbourne crime scene in the 1980s, and the Pettingills crime family. Also, the random revenge murder of two patrolmen recreates the 1988 Walsh Street police shootings.
When David Michôd was writing the part of Detective Nathan Leckie - who he envisioned as being slightly anachronistic, an old-fashioned cop in a modern world - he had the idea of Leckie wearing a mustache. When he spoke to Guy Pearce about the part, he was quite surprised when Pearce suggested that the character should sport a mustache.
In an interview on the radio program "Fresh Air," Jacki Weaver explained that her interpretation of her character included the unspoken fact that all of Janine's children had been fathered by different men, most likely criminals themselves.
David Michôd explained that among the unplanned, unscripted elements he felt compelled to add to the film's opening moments for clarity, after shooting was complete, were the stills montage of bank robberies and the voiceover by protagonist Josh/J.
Still a high school student, James Frecheville plays a character the same age as himself, though he was much bigger and more adult-looking than the character originally imagined by writer/director 'David Michôd. But Michôd very quickly realized that Frecheville's alpha-male look brought an extra credibility as well as tension to the drama.
This film effectively proved to be a breakthrough role for Sullivan Stapleton. Prior to this, Stapleton had been toiling away in small parts on Australian TV and had occasionally resorted to working as a movie grip and even as a builder.
David Michôd says his intention was to create a crime drama that was "sprawling and grand... bigger, darker and meaner" - a film that quickly departed from the bleakness of its initial drug-addicted, working-class milieu.
Filming began not long after one of the longest heat waves ever to hit Eastern Australia lasting for approximately two weeks. Melbourne, where the film was shot, recorded its hottest temperature ever during this time.
An early champion of the film was Joel Edgerton who worked hard to help drum up backers for David Michôd's script. Two years earlier, Edgerton had been in a similar position trying to get the backing necessary for his own screenplay, The Square (2008).
This film represents the third of three Australian Film Institute (AFI) acting awards won for a feature film by Australian actress Jacki Weaver. Weaver's first was Best Actress (as the Hoyts Prize for Best Performance) in Stork (1971) and the second was a tie for Best Supporting Actress, with Melissa Jaffer, both for Caddie (1976).