Protests have followed police killings in America with saddening regularity, but the scope of demonstrations following George Floyd’s murder may mark a turning point in how policing is monitored and regulated. We speak to Lee Merritt, an attorney for Mr Floyd’s family, and to our United States editor—asking how likely cultural and structural changes are to take hold. For full access to print, digital and audio editions of The Economist, subscribe here www.economist.com/intelligenceoffer