Worst were the empty playgrounds, bathed in the sunshine of that Technicolor autumn. The parks and schoolyards should have been full of children, noisy with glee, burdened by nothing more troubling than skinned knees. Instead, their silence radiated fear. That was Washington in October 2002, when a person or persons unknown sowed three weeks of terror through random sniper fire. People were killed cutting grass, pumping gas, going shopping, walking to school. Death itself, with hood and scythe, could not have been more random, more remorseless, more unnerving. Or more pointless. When at last the snipers John Allen Muhammad and his juvenile accomplice, Lee Boyd Malvo were caught, they had so little reason for murder that they hardly even tried to explain themselves. There was the older man's anger, the younger man's loneliness, a quarter-baked extortion plot. Late on Nov. 10, in a Virginia prison, it was Muhammad who paid the final price. With relatives of his victims watching, he went to his execution as vacant and silent as those deserted playgrounds. "It's over," said a witness, for there was little else to say.