Capt. Ronald Johnson of the Missouri Highway Patrol smiles at demonstrators march along West Florissant Avenue in Ferguson, Mo., on Thursday, Aug. 14, 2014. The Missouri Highway Patrol took control of a St. Louis suburb Thursday, stripping local police of their law-enforcement authority after four days of clashes between officers in riot gear and furious crowds protesting the death of an unarmed black teen shot by an officer.

St. Louis Post-Dispatch, David Carson / AP

Capt. Ronald Johnson of the Missouri Highway Patrol smiles at demonstrators march along West Florissant Avenue in Ferguson, Mo., on Thursday, Aug. 14, 2014. The Missouri Highway Patrol took control of a St. Louis suburb Thursday, stripping local police of their law-enforcement authority after four days of clashes between officers in riot gear and furious crowds protesting the death of an unarmed black teen shot by an officer.