A protester throws a tear gas canister back toward riot police after a 10 p.m. curfew went into effect in the wake of Monday's riots following the funeral for Freddie Gray, Tuesday, April 28, 2015, in Baltimore. (David Goldman/AP)
Police fire tear gas at demonstrators protesting the shooting of Michael Brown after they refused to honor the midnight curfew on August 17, 2014 in Ferguson, Missouri. The curfew was imposed on Saturday in an attempt to reign in the violence that has erupted nearly every night in the suburban St. Louis town since the shooting death of teenager Michael Brown by a Ferguson police officer on August 9.
A protester raises his hands as clouds of smoke and crowd control agents rise shortly after the deadline for a city-wide curfew passed in Baltimore, Maryland April 28, 2015, as crowds protest the death of Freddie Gray, a 25-year-old black man who died in police custody. (REUTERS/Adrees Latif)