Carol Gray, her head wrapped in a black scarf and her tearful eyes concealed by sunglasses, held up a photograph of her 16-year-old son, who was shot and killed by police.
The picture revealed a grinning boy wearing a blue cap and gown, his arms wrapped around his mother. It was taken the day he graduated from middle school.
"He was slaughtered," Gray told a room filled with reporters. "And I want to know why."