Three days after Russian opposition politician Boris Nemtsov was slain by at least four bullets in the back outside the walls of the Kremlin, there is no trace of his killer.
But politicians, activists and observers critical of President Vladimir Putin agree that, whoever pulled the trigger, Nemtsov fell victim to a climate of hate and fear that the authorities have fanned in Russia since the revolution in Ukraine and Moscow’s annexation of Crimea.
Mr Putin’s opponents had been under growing pressure since his return to the presidential office in 2012. But after Ukraine’s political upheavals began, this pressure turned into open threats.