Gun Battle in Ferguson

St. Louis County police officers shot and critically injured a man who fired at them here late Sunday night, the authorities said, setting this region on another tense and uncertain course on the same day that hundreds gathered to commemorate the anniversary of the killing of Michael Brown, a black teenager, by a white officer.

)A day of peaceful vigils to mark the one-year anniversary of Michael Brown's shooting death turned ugly late Sunday when protesters threw rocks and bottles at officers, and police critically injured a man who they say fired at them.