Sergei Yushenkov (2003). Yuri Shchekochikin (2003). Anna Politkovskaya (2006). Stanislav Markelov (2009). Anastasia Baburova (2009). Natalia Estimirova (2009).

To this sad and shameful roll call of politicians, journalists, and human rights activists assassinated in Vladimir Putin’s Russia must now be added the name of Boris Nemtsov, who was shot dead within shouting distance of the Kremlin on Friday.

Like those on the list above, Nemtsov was a stubborn champion of democratic values and human rights. His murder marks a further sickening downwards lurch in Russia’s culture of political violence. His death tears a hole in Russia’s threadbare opposition movement. One bunch of flowers left on the bridge where he was shot included the message: “Without you, spring will not come.”