Here, where heavily fortified police officers faced the demonstrators and the nights sometimes turned violent, even those shopkeepers who put in new windows are boarding up again.

“I hate this,” said Dan McMullen, the president of Solo Insurance Services, as he sat behind his desk on Thursday. During the course of a 20-minute conversation, his phone did not ring; no customers walked through the door. “Business is terrible,” he lamented. “The customers don’t want to come here anymore. We all know the grand jury is going to come back in the next couple of weeks, and everyone knows there won’t be an indictment. This time around will be a lot more violent.”…

[P]eople protesting police tactics, who have continued to hold marches here since the shooting on Aug. 9, say they envision larger, angrier demonstrations should Officer Wilson not be charged. Fearing renewed unrest, the police in the region have bought new riot gear, called meetings with nearby departments and held special training seminars.

School leaders are reviewing emergency contingency plans and urging officials to announce the grand jury finding outside of school hours — perhaps on a Sunday, so that children returning home are not caught in a melee.