The police didn't have enough physical evidence to make the case.
Where would you look for physical evidence of the building?
There could not be any physical evidence left behind of their work.
So physical evidence and theory seem to support each other.
In the end, doctors look for the parents to tell us much more than any physical evidence can.
"There had to be physical evidence of something that was said."
But she knew that in old cases like this, physical evidence was the key.
Actually, the truth was that they had way too much physical evidence.
They had their physical evidence and to hell with her!
And up into the sky went the only physical evidence of the Project.