WASHINGTON (AP) — The St. Louis suburb of Ferguson, Missouri, was roiled by racial unrest after 18-year-old Michael Brown, who was black, was shot and killed by Darren Wilson, a white police officer, on Aug. 9. The street clashes there mirrored past, larger-scale riots in multiple U.S. cities, most of them triggered by perceived racial injustice, or an incident involving police, in already tense communities. Once the troops left on July 2, a group of whites shot at blacks' homes, and blacks retaliated by killing two white police officers. After a state grand jury investigation, 144 men, including five police officers, were indicted on charges ranging from arson to murder. —On Aug.