The story of Leopold and Loeb – two young intellectual aesthetes, from wealthy Jewish families, who murdered a 14-year-old boy for kicks in Chicago in 1924 – has been filmed twice before. Rope located the roots of fascism in Nietzschean discourse. Compulsion was a more muddled ‘true crime’ saga. Kalin’s film is the least naturalistic and most factual. It is also the first to expand on Clarence Darrow’s argument for the defence, that the pair’s homosexuality was a sign of pathological deviance; ergo they were not accountable for their actions. The film’s second half sticks to court transcripts, to diagnose a repressive, racist, homophobic pathology on a wider social scale, endemic to patriarchy itself. Sketched in deft, sharp strokes, this is no more than a postscript to the earlier exploration of the lovers’ sado-masochistic relationship: how Loeb bartered crime for sex, and how their transgressive games escalated to the point of no return. With its sinuous monochrome finish, Swoon is decadent and economical, subjective and detached, fascinating and appalling – conjunctions Sacher Masoch himself might have recognised.