We can argue the relative merits of adapting true events into fictional entertainment forever, and it is unlikely that we would ever reach a consensus. When we argue over adaptations of true events that involve death, tragedy, and murder, the debate will surely be particularly heated. ‘True crime’ is something for which the mainstream has become particularly fond, despite reasonable criticism that such fiction makes entertainment out of human suffering. For survivors of a tragedy or a criminal act, having one’s own trauma replayed for the enjoyment of strangers must be utterly inexplicable in its cruelty. At the same time, translating incomprehensible tragedy into a coherent narrative allows us as a community to process difficult topics. In April 1996 a lone individual went to Port Arthur, in the Australian island state of Tasmania, and murdered 35 people in a mass shooting. It seems impossible for a sane mind to comprehend why someone would do that. Perhaps Justin Kurzel’s new film Nitram may enable Australians to process that event better.

It has certainly been a contentious project since it was first announced. The Port Arthur Massacre, as it is widely named, was a pivotal event for Australia at the end of the last century. It is necessary for non-Australians to realise that spree killings of this nature are not commonplace in this country. The events at Port Arthur still mark the deadliest mass killing undertaken in modern Australian history (which – let us make this clear – means the worst massacre not to involve government-sanctioned white colonists committing mass murder against Aboriginal Australians). As a result of the Port Arthur Massacre, Australia’s gun laws were significantly overhauled and more than 600,000 firearms were purchased by the Federal government from the community simply to get them out of circulation. The entire episode is something of an open wound to Australian culture, so it is no surprise that many people in the country found the idea of making a film about the perpetrator to be in poor taste at best.

I do not personally believe there is a subject matter out there that cannot be translated to narrative film in one form or another. The more difficult the matter, however, the more responsibility is placed in the filmmaker’s hands to adapt it in a manner that is sensitive, intelligent, and morally responsible. To their credit, Kurzel and screenwriter Shaun Grant do a hell of a lot to mitigate the inevitable offence Nitram will cause. First and foremost, the film does not reproduce the spree killing on screen. In addition, and arguably more significantly, the perpetrator is never fully named either in dialogue or captions. In the spirit of that choice, the perpetrator will not be named in this review.

Nitram is not a film about a mass murder. It is a film about the kind of mind that would consider committing one, and the environment within which that individual could actually undertake it in real life. Finding such a film distasteful is an understandable, and even sensible, reaction, but it is essential to acknowledge that this is a responsible, mature work of art. To not tolerate it is as simple as not watching it.

This is not an entirely unique film either. In 2017 American filmmaker Marc Meyers directed My Friend Dahmer, adapting an earlier graphic novel by John Backderf about going to high school with notorious serial killer Jeffrey Dahmer. On a similar level, Meyers’ film excludes any of Dahmer’s crimes and instead shows what he was like as a teenager. The film reveals his obvious mental illness as well as the inhuman manner in which his growing troubles get conveniently ignored by parents, peers, and teachers until it is too late. Clearly there are differences – Meyers’ film invites audience sympathy in a manner that Kurzel’s does not – but in both cases there is a visible goal to move away from easy perspectives on murderers as evil monsters and to approach them with a uncomfortable humanistic eye.

Kurzel’s film employs a slow build that brings it a sense of rising dread. I do wonder if this growing sense of inevitability would be quite so keenly felt by viewers unfamiliar with the historical events that Nitram creeps toward. If it is, it will likely be thanks to the central performance by Caleb Landry Jones – so effective and unsettling that it scored him Best Actor at the Cannes Film Festival. It is a difficult performance to watch, because it is so spectacularly impenetrable. It is hard to comprehend the character’s actions and moment-to-moment motivations, beyond a general sense of ‘wrongness’.

The emotional entrance to Nitram is, instead through the protagonist’s parents. Judy Davis and Anthony LaPaglia are both superb. Each responds to their difficult, impossible child in different ways. For Davis it means portraying a simmering and miserable resentment: a maternal love that has been hollowed out and replaced with a constant low-boiling hate. For LaPaglia it means a broken-down sense of defeat. He is the one who has stumbled away from real parenting to simply walking two steps behind and making excuses. It has clearly shattered the marriage. Between the two actors it is a marvel of soft, rotten misery.

Essie Davis also appears as an eccentric neighbour who forms an unusual relationship with the protagonist, and whose own psychological issues appear to render her incapable of recognising his. It is a third path to study his behaviour, but feels less successful than those expressed by Davis and LaPaglia. Frankly if it was not based on real events and people, Davis’ presence would beggar belief.

This is a difficult, miserable film. Given the subject matter it needs to be. We are, all of us, too ready to write off unimaginable crimes as the work of ‘evil’. In a way that frees us from a second horror. Serial killers, spree shooters, and the like: they are never born but made. Each choice made by friends, family, and broader society edges them closer and breaks things further until the violence in inevitable. What if the killer’s mother treated him differently? What if his neighbour had reacted differently to him? What if his father had stood up to his behaviour? What if the gun dealer – played by actor Rick James in a truly nauseating scene of weak gun laws and corner-cutting – observed the law or sensed the elephant in the room. There is only one killer, but I cannot shake the sense than countless people, over many years, pulled the trigger. Nitram is a deeply uncomfortable and masterful tragedy.