Baltimore City State's Attorney Marilyn J. Mosby announces that criminal charges will be filed against Baltimore police officers in the death of Freddie Gray in Baltimore on Friday. Gray died in police custody after being arrested on April 12. Andrew Burton/Getty Images hide caption

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Detective Mark Williams (right) speaks with an officer in Richmond, Va. A decade ago, amid a surge in violent crime, Richmond police were identifying relatively few murder suspects. So the police department refocused its efforts to bring up its "clearance rate." Alex Matzke for NPR hide caption

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This undated photo taken from the Kaufman County, Texas, website shows Kaufman County District Attorney Mike McLelland. McLelland and his wife were found killed in their house on Saturday. AP hide caption

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