Slate writes, NEW YORK CITY—The Cannibal Cop sits in court, chubby-cheeked, with his chin in the palm of his hand. Though he faces life in prison if convicted—he's been charged with "a heinous plot to kidnap, rape, murder and cannibalize a number of very real women"—the former New York City police officer barely says a word. Gilberto Valle slouches forward in his seat and holds that pose for hours, while the details of his sexual sadism—plans to cook his friends alive and worse—are read off and posted to a monitor beside him. If this embarrasses Valle, we wouldn't know. If it angers him, it's hard…