Russian opposition leader Boris Nemtsov gunned down in Moscow

A fierce critic of Russian President Vladimir Putin, Boris Nemtsov, is gunned down in heavily policed streets just yards from the Kremlin. Will we ever know who killed him? .Sign up for Snowmail, your daily preview of what is on Channel 4 News, sent straight to your inbox, here: Missed Channel 4 News? Catch up on the last seven days here: Channel 4 News weather forecast, with Liam Dutton: All the latest blog posts from the Channel 4 News on-screen talent: