The great James Cagney, top-billed in big letters, doesn't show up till the movie's second third, and probably has less screen time than Dudley Digges, who plays the eee-vill reform-school potentate. But when Jimmy arrives, as a deputy commissioner of something-or-other out to reform reform schools, he slashes the air with his hands and jumps on the balls of his feet and spits out punchy Warners-First National dialogue with all the customary, and expected, panache. The psychology in this crisp antique, one of Warners' many efforts to assert its place as the "socially conscious" studio, doesn't run deep: Digges is bad just because the script requires him to be, and there's the quaint notion that juvenile delinquents will turn into swell kids if they're just given a dash of autonomy. But it's made in that spare, fast style that the studio specialized in, and it never bores. Frankie Darro, who got into all kinds of onscreen trouble during a brief tenure as Warners' favorite Rotten Street Kid, is an ideal JD -- a handsome, charismatic toughie with a pug nose and a hate-filled stare that could wither steel. No kid actor today can touch him.