If Russia is innocent then why is it not doing far more to help international investigators gain full, unhindered, access to the crash site? Why am I suspicious? If they have nothing to hide why all the secrecy? All the Russian actions appear to show ever more complicity.
It would be better for Russia to "come clean" and admit that Russian backed separatists shot the plane down. Admit Russia was unable to control rebel factions and then move on. As it is, Russia is likely to face tougher sanctions and yet more isolation in the international community. Both actions are not in Russia's best interests.
It would be in Russia's best interest to agree a permanent downing of weapons in Ukraine and to hold elections to decide the future of Russian speaking regions of Ukraine, perhaps under UN control (of elections)? If some parts want to move to Russia, then let them go. Bombs and bullets do not solve such conflicts.
UPDATE 1612z: http://www.bbc.co.uk/news/world-europe-28389991