A great “video nasty” breaches the boundaries of good taste, finding something uncomfortably real behind them. Many video nasties lose their impact over time as censorship slackens, but that’s not the case with Maniac.

This is thanks to Joe Spinell’s sweaty anti-charisma as the titular maniac, Frank Zito, combined with Tom Savini’s legendary makeup work (he’s an artist with a shotgun, to paraphrase Miller’s Crossing). Most slashers rely on the queasy tension between killer and victim; we try to sympathise with the victims but the voyeuristic camera means we often find ourselves siding with the shadowy figure stalking them. Maniac’s structure avoids even the thinnest characterisation for its victims – you’re with Zito every step of the way. Three decades later, it remains deeply disturbing.

It’s less effective when it tries to explain Zito’s mania. Video nasties aren’t the best place for a nuanced examination of psychosexual trauma. His lurid flashbacks and hallucinations are visually compelling – 8½ or a zombie film filtered through VHS – but not especially psychologically profound. This is amplified when Zito, implausibly, manages to romance a beautiful young photographer; the most discomfiting thing about Maniac is the idea that someone this damaged could pass as normal, however briefly.