The following is a guest blog post from Alan McPherson, author of Ghosts of Sheridan Circle: How a Washington Assassination Brought Pinochet's Terror State to Justice. On September 21, 1976, a car bomb killed Orlando Letelier, the former Chilean ambassador to the United States, along with his colleague Ronni Moffitt. The murder shocked the world, especially because of its setting--Sheridan Circle, in the heart of Washington, D.C. Letelier’s widow and her allies immediately suspected the secret police of Chilean dictator Augusto Pinochet, who eliminated opponents around the world. Because U.S. political leaders saw the tyrant...