It so happens that the penchant for ripping procedural melodrama from the headlines is not exclusively American. The French have been doing it beautifully for generations. Polisse, an extraordinary ensemble drama from 2011 just now arriving stateside, plays out very much like a grand, Gallic episode of Law & Order SVU. But instead of tautly topical formula best-suited to a half-watched TV, it sprawls with unruly big-screen dynamism — and doesn’t dare let go of your attention. As seen by a shy photographer, played by director/co-writer/force of nature Maïwenn Le Besco — or, as the credits call her, just “Maïwenn” — it’s ostensibly a group portrait of short-fused cops at the child protection unit. “We don’t judge; we don’t care,” one officer says, coaxing a confession, and it is the movie’s great privilege to investigate that claim. What’s miraculous is the degree of lyricism it derives from unquenchable and innately compassionate psychological curiosity.