FILE - Police investigate the body of Boris Nemtsov, an opposition leader and a former deputy prime minister, with the St. Basil's Cathedral and Red Square in the background in Moscow, Russia on Feb. 28, 2015. Boris Nemtsov, a top figure of Russia's beleaguered political opposition, is gunned down on a bridge next to the Kremlin. Nemtsov was working on a report about Russian soldiers in eastern Ukraine. (AP Foto/Pavel Golovkin, File)