Evidence, that has yet to be refuted.
5 to 7 solid witnesses and co-conspirators.
Unimpeachable corroboration.
Proving criminal intent/state of mind?
And if one of the measurables is surviving appeal.
Not impossible, but offa! That's one helluva slog. And as Jar noted a few days ago, juries are a different animal altogether. So if you win, he's a martyr and more powerful than ever. If you lose he beat the system that done him dirty and he's more powerful than ever.
Aside from the criminal "stuff" I hope someone is keeping an eye on the political implications of all this. I think they are. I hope they are.