In the aftermath of Boris Nemtsov’s murder, it has become clear to me that Russia is entering a new era. An era when the audacious murder of a protest leader is possible. The era of permissiveness. And although it seems that we have entered this era overnight, this environment of intolerance of dissent has been building up over several years.

A pervasive culture of impunity, the apparent lack of political will to find and bring to justice all those involved in human rights violations, have all significantly contributed to creating this atmosphere. We have been witnessing its exponential growth day by day with smear propaganda flowing from the state-owned media and insults splashed on all those whose opinion differs from the Kremlin’s line.

Before his death, Boris Nemtsov had been planning a protest to take place on 1 March – the first day of spring – hence it was dubbed ‘the Spring March’. Organizers, including well-known opposition leaders, wanted to hold it in the centre of Moscow, but were forced to back down and hold it in the outskirts of the city. People were not happy about this and a low turnout was expected.

Mourners placed flowers at the site near the Kremlin where Boris Nemtsov was killed. © Amnesty International

But everything changed overnight. On Saturday 28 February at 4AM I received an unusual email from an unknown person which shattered me totally. It read “Boris Nemtsov was killed in Moscow”. Boris, the former vice prime minister in Yeltsin’s cabinet, was assassinated on the eve of the protest event he had been organizing?

I had no doubt it was true.

In spite of the Moscow authorities’ initial unwillingness to allow the march to take place in the city centre, common sense won out.

Fifty thousand Muscovites walked slowly towards the bridge near the Kremlin where Boris was felled by four bullets, passing by the spot where he was killed. The protesters held thousands of Russian flags with black ribbons, and they placed flowers all over the bridge railings. There were placards everywhere with photos of Boris.

I see a tragic symbolism in the killing of one of the most active advocates of freedom in Russia on the very same bridge where, just a year ago, seven Directors of European sections of Amnesty International stood in a picket demanding freedom of peaceful assembly.

Several Amnesty International Section Directors take part in a picket for freedom of peaceful assembly in January 2014, on the same Moscow bridge where Boris Nemtsov was killed more than a year later. © Amnesty International

These are very depressing days for those who shared Boris’s values. The future will show whether people in Russia are prepared to tolerate such a society, where dissenting voices are silenced by killers. Sergei Nikitin, Amnesty International's Moscow Office Director

But it is encouraging that there are still people who are not frightened – many thousands of people who are not scared to walk down the Kremlin bridge in silent protest; who are not scared to protect human rights despite hysterical accusations about them being “foreign agents”, spies, and traitors; who are not scared to speak truth to power in blogs, articles or interviews with the handful of surviving independent media outlets.

They all understand that this spring has opened a season when one can easily be attacked and even be killed for speaking their minds. The brave people in Russia may still be a tiny minority for such a huge country. But the mere fact that they do exist, and their enthusiasm, charisma and self-confidence, gives me hope in these dark days. Russia will be free; the question is when, and at what price? The alternative is that spring may turn straight into winter.