Steve,
What absolute nonsense. Enough direct accusation has been made against Russia from on high by the great and the good to make any "fair trial" against Russia completely impossible.

You can not put a country in the dock, silly.
In the Alexander Litvinenko case, the agent accused of administering the poison would have been tried if we could have extradited him.

Russia was openly accused in that case as in this.
As I said, the details of the investigation were not released as the evidence was found. That never happens.
Do you really believe that no evidence has yet been find by either police or security services, or that the scientists know nothing but the general type of nerve agent?
How naive!