moscow tv station purports to be boris nemtsov and his girlfriend. nemtsov was, of course, the well-known russian opposition leader who led the protests in 2011. the station says that while the snowplow hides the two from cameras view nemtsov was killed, shot four times in the back. >> a prominent russian opposition figure has been shot and killed. >> four of the shots hit him in the back. >> right out in the open, just blocks from the kremlin. >> so who murdered boris nemtsov? vladimir putin condemned the killing calling it shameful and impudent, and five chechens are found guilty in connection with the murder. but many doubts remain. >> the assassination was extremely professional. >> russian-born journalist julia joffey said only one group could be that professional. >> nemtsov's girlfriend, who was