A girl lays flowers on the murder site of Russian opposition leader Boris Nemtsov in Moscow, Russia, on Feb. 28, 2015. People came to the murder site of Boris Nemtsov for mourning on Saturday. Boris Nemtsov was shot and killed near the city center on Feb. 27, 2015. (Xinhua/Dai Tianfang)

A man lays flowers on the murder site of Russian opposition leader Boris Nemtsov in Moscow, Russia, on Feb. 28, 2015. People came to the murder site of Boris Nemtsov for mourning on Saturday. Boris Nemtsov was shot and killed near the city center on Feb. 27, 2015. (Xinhua/Dai Tianfang)

People lay flowers on the murder site of Russian opposition leader Boris Nemtsov in Moscow, Russia, on Feb. 28, 2015. People came to the murder site of Boris Nemtsov for mourning here on Saturday. Boris Nemtsov was shot and killed near the city center on Feb. 27, 2015. (Xinhua/Dai Tianfang)