Tavernier's second film is virtually a two-hander between Tavernier regular Philippe Noiret (the judge) and Michel Galabru (the assassin). Galabru's performance has a terrifying ferocity and conviction as the seriel killer of small children who is clearly insane, but who can still use logic within his insanity to point up the hypocrisy of the society he lives in. Galabru, who up to this point had been mainly known for light comedy, is somehow freed up by this character to take down all internal censors; he throws himself into it unreservedly.
By contrast Noiret is cold, calculating, emotionally stunted and reticent. The contrasts between the two are intense - middle class vs working class, soldier vs. civilian, anarchist vs. conservative. And yet Tavernier seems to be saying that the judge is in some way the assassin and the assassin the judge. The judge can see that Bouvier is insane, but insists that he's play-acting, because his sense of revenge requires that Bouvier goes to the guillotine.
This is a historical film set in the 1890s, and the Dreyfus case is in the background, ultimate manifestation of the corruption of justice by an intensely anti-semitic society. Tavernier suggests, but doesn't hammer the point, that there are parallels between Bouvier's case and Dreyfus's.
He also suggests that the impulses in Bouvier are in all of us. This is why, after Bouvier has confessed to killing and anally raping some of his victims, the Judge has to go and force sodomy on his reluctant mistress (Isabel Huppert).
As often happens in Tavernier, some of the crucial scenes in the plot development happen offscreen - we never see the execution for example, which the Judge has worked so hard for. Instead we get an intensely felt and intensely argued film, almost a philosophical dialogue, about the nature of crime, sanity and responsibility.
The film closes with an epigraph: Bouvier killed 12 children between 1893 and 1896; in the same period 2,500 children died working in French mines. This is an uncharacteristically angry film from Tavernier, but he never lets his anger divert him from telling the story through the characters.