... police departments are preparing behind the scenes for what could be a weekend of chaos Sergeant Betsy Brantner Smith, a retired 20 year veteran, said violence is 'likely' and it may start tonight The fact the verdict came in on a Friday means more people are likely to protest because they aren't at work It also came in late so it will be darker sooner in much of the country than it was in August last year She said forces must use a zero tolerance policy but that local, state and federal leaders need to urge calm too