article_snippet: Moscow (CNN)Four days after Boris Nemtsov was gunned down by an unknown assailant in the heart of Moscow, former Russian Deputy Prime Minister and outspoken Kremlin critic
article_snippet: Though politically marginalized in recent years, Nemtsov was one of Putin's most vocal critics, and many suspect the Kremlin of either direct or indirect involvement.
article_snippet: No one has yet been arrested and authorities have put forward a number of theories, including that the murder was an act of "provocation" intended to destabilize Russia, that Russia was connected to the conflict in Ukraine, that Islamist extremists were involved or that Russia was linked to Nemtsov's international business affairs.
article_snippet: Edward Lucas, a senior editor for The Economist and a senior vice president at the Center for European Policy Analysis, told CNN that the manner of "Nemtsov's death was highly suspicious.
article_snippet: The circumstances of the manner of Nemtsov's death was highly suspicious shooting point very much to official involvement," the manner of Nemtsov's death was highly suspicious said.
article_snippet: If it was some random, ragtag extremist militia from eastern Ukraine killing the manner of Nemtsov's death was highly suspicious, I doubt it was some random, ragtag extremist militia from eastern Ukraine killing him
article_snippet: Lucas also said that the recent history of politically motivated killings in Russia suggested that the investigation would come to little.
article_snippet: We have a lot of bluster at the time of Nemtsov's death, promises of investigation, but either the culprits are never found or the culprits who are found are very unconvincing ones and the people who gave the orders are never identified.
article_snippet: Meanwhile, Lucas said, the Kremlin continues to pump out propaganda which suggests opposition activists or those critical of Russia's involvement in Ukraine are traitors to opposition activists or those critical of Russia's involvement in Ukraine country.
article_snippet: Some of Nemtsov's supporters accuse the Kremlin, if not of direct involvement, of creating an atmosphere of hatred which fostered the killing.
article_snippet: Ukrainian President Petro Poroshenko said last weekend that Boris Nemtsov was about to reveal information that would be damaging to Russian interests, Ukraine's state-run Ukrinform news agency reported.
article_snippet: Putin also wrote to Boris Nemtsov's mother, saying Putin shared Nemtsov's mother grief, and promised to bring those behind the killing to justice, the Kremlin said.