It seems that the launch site has been rather precisely determined. Perhaps you missed that memo.
And no matter how much evidence the US or Ukrainian government produces, no matter how detailed and annotated, Russia will dismiss it with a wave of a hand as fabricated, slanted, biased...whatever they want. They'll never admit responsibility.
What they need to do is to organize UN peacekeeper mission there, not wage proxy war with US.
Yes, because UN peacekeepers have such a long, sterling reputation on stopping stuff like this from happening.
But regardless, the UN will never do anything in this conflict. Russia holds a veto in the Security Council, and they will stop any such measures from ever happening.
How can you do 'New Math' problems with an 'Old Math' mind? -- Charles Schulz