Editor’s Note: Jill Dougherty is a public policy scholar at the Woodrow Wilson International Center for Scholars in Washington. She is a former CNN correspondent who spent almost a decade as the network’s Moscow bureau chief and correspondent. She is writing a book about Russian President Vladimir Putin. The views expressed are her own.

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Russian opposition leader Boris Nemtsov was killed last month

Jill Dougherty: Conspiracy theories about the killing are rife, but none seem convincing

CNN  — 

Russian police moved with surprising speed to arrest five suspects, all of them Chechens, in the killing of opposition figure Boris Nemtsov. They tried to arrest a sixth suspect, but he reportedly threw a grenade at the arresting officers and then blew himself up. Yet that speed has only raised more questions about who wanted Nemtsov dead – and why?

Conspiracy theories are rife, but so far, none seem totally convincing.

? The Kremlin did it. Some members of Russia’s opposition – and Nemtsov’s daughter – are convinced Russia’s government was behind Nemtsov’s killing. But why? And why now? Nemtsov, 55, had been an opposition leader for years and had recently been overshadowed by younger members of the opposition such as Alexey Navalny. So killing him now doesn’t seem to make sense.

Some of Nemtsov’s supporters claim he had become a bigger threat to the Kremlin, pointing to information he was allegedly uncovering on Russia’s military role in Ukraine that could undermine the Kremlin’s claims that its forces fighting in Ukraine have been just “volunteers.” But the dramatic staging of the killing – he was shot in the back on a famous Moscow bridge against the backdrop of Red Square and the Kremlin, where Putin has his office – seems a bit too obvious. And how exactly does it help Putin to look like a killer?

? The West did it. Some Russian politicians and media personalities close to the Kremlin charge that Putin’s foes in the West orchestrated the killing to damage the Russian President’s image and ignite a civil war in Russia. But why would Washington want to destroy someone who was championing democracy and who is friendly to the United States? (Conspiracy theorists reply: to create a “sacrificial lamb” and blame the slaughter on Putin.)

? It was the Chechens. Here, the plot thickens. The key suspect, Zaur Dadayev, reportedly initially confessed to being involved with the shooting. But then, Russian media reported, he denied involvement. Russian officials have alleged that Dadayev, a former security officer and fervent Muslim, decided to punish Nemtsov for supporting the rights of the French Charlie Hebdo journalists to publish cartoons of the Prophet Mohammed.

But Nemtsov’s allies point out that he was not anti-Muslim and rarely spoke of the cartoons – he was by no means a central figure in the cartoon story. To make things more complicated, the strongman leader of Chechnya, Ramzan Kadyrov, praised Dadayev as a brave soldier, a religious man and a “real patriot.” But on Tuesday, Putin awarded Kadyrov the Order of Honor, and the Chechen leader pledged he would die for Putin.

A further twist is that Chechens reportedly are fighting in Ukraine – on both sides of the battle line (for the Ukrainian government and for the Russian-allied separatists.) That’s led some back to the theory that Nemtsov was killed because of his allegedly explosive information on Russia’s role in Ukraine.

? The Ukrainians did it. Many Russians are convinced that what they call the “fascist” Kiev government would stop at nothing to frame Putin. After all, a significant number of people, fed by domestic propaganda, still believe the Ukrainian air force shot down Malaysian Airlines Flight 17 over Ukraine despite much of the evidence pointing to Russian-backed rebels as the culprits.

? It was domestic extremists. Supporters of this theory are mainly in the opposition camp. They accuse the Kremlin of whipping up hatred against the so-called Fifth Column – “traitors” who are trying to undermine Russia from within.Photos of opposition leaders labeled “traitors” have been posted in Russian cities, while at an anti-Ukraine rally in Moscow just days before Nemtsov’s assassination, Russians loyal to Putin carried signs and placards with pictures of those “traitors,” including Nemtsov.

But whatever the reality of what happened in Moscow, high-profile killings in Russia, especially ones with a political connection, are rarely solved. Chechens were convicted of killing journalist Anna Politkovskaya, for example, but there still is no explanation of why they did it or who organized the murder.

Now, with Nemtsov’s killing, Russian officials and Kremlin-friendly media have whipped up a sandstorm of theories, confounding the most intrepid attempts at establishing the truth. Will things play out any differently this time?

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