St. Louis County Police and Missouri State Highway Patrol troopers (C) stand guard as protesters (foreground) march on West Florissant Avenue in Ferguson, Missouri on August 9, 2015.  A day of peaceful remembrance marking the anniversary of 18-year-old black teen Michael Brown's killing by police in the US city of Ferguson came to a violent end on August 9 as gunfire left at least one protester injured.       AFP PHOTO / MICHAEL B. THOMAS        (Photo credit should read Michael B. Thomas/AFP/Getty Images)