No one knows for sure how many people were murdered during Stalin's Great Purge, but estimates put the figure at more than 1 million. During the peak period of 1937-38, Stalin's secret police executed more than 1,000 people per day, most with a shot to the back of the head. These photos show some of the victims in their last weeks or days. The original photographs were saved in FSB and GARK archives. Copies were provided by the international association Memorial in Moscow and were taken from "The Great Terror in the USSR 1937-1938" by Tomasz Kizny, in cooperation with Dominique Roynette, Les Editions Noir sur Blanc, Lausanne 2013. (8 PHOTOS)