It was a wolf whistle that turned into a racial whirlwind. It was a cheeky moment when a high-spirited, 14-year-old black kid visiting from Chicago forgot where he was and, while buying bubblegum with his cousins at the store in the dirt-poor, redneck village of Money, Mississippi, acted "sassy" before the white storekeeper's pretty, young wife. Emmett Till paid for it a few nights later with his life, suffering a grotesque, tortuous lynching. Finally, shot through the head, wrapped in barbed wire and weighed down, he was thrown into the Tallahatchie River. Only the signet ring left him by his late father could safely identify him. That took place in August 1955, as we see in The Murder of Emmett Till, a grimly riveting documentary from black American filmmaker Stanley Nelson.