Police departments in several major cities were bracing for large demonstrations as people across the country planned to hold protests even before they know whether a grand jury has indicted a white police officer who killed a black 18-year-old in Ferguson, Missouri. Activists from Los Angeles to New York scheduled marches and rallies to coincide with Monday evening's expected announcement of the grand jury's decision. In Ferguson, the shooting led to nightly protests that sometimes turned violent, with demonstrators throwing Molotov cocktails and police firing smoke canisters, tear gas and rubber bullets. Denver Mayor Michael Hancock urged protesters to be peaceful in that city, where a civil jury last month found deputies used excessive force in the death of a homeless street preacher.