Cinema: Some Kind of Genius

He was the Caliban of the concrete wilderness, a tough-minded, quick-fisted, devilishly engaging city sprite, the first such in movie history and still, a half-century later, the best. One minute he would be walking the dark side of the mean streets, personifying the gangster as a tragically overreaching hero (The Public Enemy); the next he was to be found quickstepping on his jaunty dancer's pins along the sunny side, tapping out a dandy Yankee Doodle up tune. But it made no difference where he traded slick jabs and smart-mouthed gibes, for he always...