“All I know is that I wanted to see what the insides of these animals looked like,” says serial killer Jeffrey Dahmer, recalling his teenage pastime of finding animals and cutting them up. The opening scene of My Friend Dahmer – the new film about his school years – has Jeffrey (Ross Lynch) stare out of a schoolbus window at a dead carcass lying mangled in the road. Later, Dahmer shows two teenagers his collection of dead animals kept in jars of acid.

These gruesome early experiences could be seen as tame compared to the 17 murders he committed between ’78 and ’91, many of which involved rape and dismemberment, but the film’s foreshadowing is frightening enough, as writer-director Marc Meyers slowly reveals certain snapshots of Dahmer’s adolescence – developing like polaroid pictures. He goes to school like everyone else, feels awkward like everyone else, tells jokes like everyone else – and we know what he’s going to grow up to become. But what is most disturbing about the film is not Dahmer’s insanity, but his normality.

my friend dahmer movie poster

Based on the graphic novel-memoir by John Backderf, who befriended Dahmer at school, the film tracks Jeffrey’s coming-of-age in ‘70s Ohio. He lives with his encouraging but inadequate father (Dallas Roberts) and clinically anxious mother (Anne Heche), who constantly fight with one another. After seeing an interior designer with cerebral palsy (Adam Kroloff), Dahmer impersonates him at school – referred to as “spazzing out”. This leads him to be ingratiated into John Backderf’s (Alex Wolff) group of friends, who “spaz out” with him and start a Dahmer Fan Club.

The film unfolds a bit like Lars von Trier’s early Dogma ’95 film The Idiots, where a gang would also gather together and pretend to be spasticated. Jeffrey uses this exaggerated and offensive display to get closer to people. But although it’s bizarre and troubling to watch, we can’t help but compare it to our own playground memories – using shocking jokes to make our friends laugh. In this respect, is Jeffrey really different from the other kids? I suppose preserving dead animals and plotting to murder joggers would make you beg to differ, but that’s kept mostly to himself. Interacting with him, shaking his hand, you’d think he was odd but not a savage killer.

There’s rarely a shot in Daniel Katz’s brooding cinematography that doesn’t have Jeffrey in it, fleshing out Ross Lynch’s dark and icy performance. He often floats subtly into frame like a phantom. Lynch isn’t totally emotionless (making the character even more frightening), but it’s not long before he returns to his natural, ominous stare. We’re almost afraid that he’ll glaze his eyes towards us, see us, and come after us in our comfortable cinema-seats.

Marc Meyers is scaldingly, perfectly patient in his writing and direction – never feeling the need to rush. Every scene, every line, every sound is like fire coursing through your bones. One scene in particular – towards the end – is so stretched and tense that it’s as if Jeffrey has absorbed you into the screen. My Friend Dahmer joins Mindhunter and the recent Lynne Ramsay thriller You Were Never Really Here as a psycho-drama that doesn’t rely on blood to grab you by the throat. The hard reality of Jeffrey Dahmer grows like an open wound inside our souls, bleeding long after we’ve left the cinema. I’m still healing.

My Friend Dahmer is released in the UK on 1st June 2018