Whether viewed from the desk of a police chief, a city mayor, or a citizen in a deprived, high-crime community, maintaining the balance between police effectiveness and fair policing is complicated and difficult to achieve, let alone to sustain over the long term. However, it is at the heart of good policing, for when policing goes out of that balance—as happened in Brixton, London in the 1970s (1) and more recently in Ferguson, Missouri (2)—the outcome can be a major breakdown in law and order, with wider, rippling consequences for our societies