Thomas Quick was the assumed name of Sture Bergwall, a patient in a Swedish psychiatric hospital who in the 90s confessed to more than 30 murders and become known as his country’s Hannibal Lecter. But there turned out to be more – or rather, less – to his story than met the eye. This British-made documentary is consistently intriguing, but its thriller atmospherics and dramatised re-enactments rather muddy the water of an already murky story. Bergwall himself appears, unnervingly calm and affable, but the film never quite allows him, or his complex psyche, the breathing space they demand. Given that the gullibility of Sweden’s institutions is at issue, the film itself could have used the more focused lucidity that it calls for.