Nitram review – deeply disturbing drama about mass killer Martin Bryant

Australian director Justin Kurzel has made his most purely disturbing film since his debut Snowtown in 2011. Like that film, Nitram is based on a real-life case of murder and family dysfunction (which incidentally also applies to Kurzel’s version of Macbeth). And he has four outstanding performances from Judy Davis, Essie Davis, Anthony LaPaglia and Caleb Landry Jones.

The Port Arthur massacre in 1996 was perpetrated by a violently disturbed young man, Martin Bryant, who shot and killed 35 people at a Tasmanian tourist site with a semi-automatic rifle bought legally; he was apparently inspired by the UK’s Dunblane massacre one month earlier. The Australian government took immediate steps to limit the sales of weaponry. Kurzel and screenwriter Shaun Grant have dramatised Bryant’s own deeply disturbed home and family environment and the utterly bizarre twists that his life had taken in the time leading up to the shooting. His pre-murder existence has a stranger-than-fiction quality that would be worthy of feature film treatment, even if the killings had never happened.

The twentysomething Bryant, played (perhaps on typecasting terms) by Jones, is a belligerent young man who is chillingly out of control, his already unstable personality made worse by the relentless bullying he suffered at school and his nasty nickname “Nitram” (“Martin” spelled backwards). Looking after this aggressive, violent child has reduced his parents to ghosts of their former selves. His dad (LaPaglia) is a weak and pathetic character. In discipline terms, he is the spineless “good cop” to the “bad cop” acted out by Martin’s fierce and shrivelled mum (an excellent performance from Davis) who has lost all hope that Martin can ever love her or learn to be a normal person.

But then a kind of miracle happens. Martin makes a half-hearted attempt to earn money by knocking on people’s doors offering to cut their lawns with a mower he’s lugging around with him, and the one person who says yes is Helen Harvey (superbly played by Essie Davis), a wealthy and reclusive heiress who takes a shine to him, buying the teenager cars and clothes and inviting him to live with her, sparking complex rage and fear in his mother, who has longed to be rid of Martin but also is hurt that he now has this alternative mother-slash-lover figure. And when Helen dies in questionable circumstances, Martin becomes extremely rich – rich enough to buy guns.

This is Martin Bryant’s bizarre life: living with someone whom Essie Davis portrays as like Little Edie in the Maysles brothers’ documentary Grey Gardens, or maybe like Norma Desmond in Sunset Boulevard. If Helen Harvey had stayed alive, then the relationship between the two of them might well have become mythologised and adapted for the movies on quite different terms.

But then came the grotesque shooting. Kurzel has chosen not to show the violence, leaving it to the very end, and off-camera. It’s a decision that makes sense, and the result is very different from, say, the two recent movies about the Anders Breivik shooting of young people at a socialist summer camp – Paul Greengrass’s July 22 and Eric Poppe’s Utøya July 22 – which in their different ways sought to confront the actual horror.

Might there be something evasive in Kurzel’s decision not to show the climactically evil moment of Bryant’s existence? I don’t think so. Scenes like those might overbalance the film, which has so intriguingly shown Bryant’s strange, looming intensity, the floating strangeness of his thoughts, mixed with the nauseous boredom and aimlessness of his simmering existence. Nitram is more like something by Gus Van Sant, and his 2003 school-shooting movie Elephant, whose lead character bears a real resemblance to Bryant.

One thing strikes me about this film. I think I assumed that Bryant would have taken his own life, having completed his horrific massacre, like so many US school shooters. But no. Bryant is still alive – something that isn’t clear from this film – serving 35 life sentences with no parole. Will he ever see this film in prison? It is a strange thought. Nitram is a hypnotically disquieting movie.

• Nitram screened at the Cannes film festival and is released in the UK on 1 July.