Una delle foto d'archivio rese pubbliche che documentano l'esecuzione

FILE - In this May 1943 file photo, two German officers, left, and a group of Allied officers who were prisoners of war look over a partly-emptied mass grave in the Katyn Forest in Russia. Russia’s state archives posted documents Wednesday April 28, 2010 for the first time on the Internet about the Soviet Union’s World War II massacre of more than 20,000 Polish officers and other prominent citizens. The step was a gesture to Poland in a case that looms large in Polish history and has soured relations between the two countries for decades. (AP Photo, File)