If there was no snow on the ground last night, and when you wake up in the morning the ground is covered with snow, it is a reasonable deduction that it snowed during the night.
But, to conspiracy theorists and True Believers, if you didn't actually see it snow, then you do not know it snowed for certain, and it's possible there is some other explanation -- like a sinister government plot.
This is evidently why conspiracy theorists and True Believers cannot accept or understand circumstantial evidence. Circumstantial evidence requires making a deduction about things not actually witnessed, but for which there is sufficient evidence to make a logical deduction. Example:
1. An abundance of facts say that Bruce Ivins was the anthrax mailer.
2. The facts say that the letters were mailed from Princeton, 200 miles from where Ivins lived.
3. The facts say that Ivins would sometimes drive hundreds of miles to play tricks on people.
4. The facts say Ivins acted alone to send the anthrax letters.
5. The facts say Ivins could do this without his family knowing what he did.But, to conspiracy theorists and True Believers, if there are no actual witnesses who saw Ivins drive to Princeton and mail the letters, then there is no proof or evidence that Ivins drove to Princeton.
It can be deduced from the facts that Ivins drove to Princeton and back to mail the letters.
Nothing could be further from the truth, and that reasoning is disputed by countless thousands of criminal trials which successfully used circumstantial evidence.
Conspiracy theorists and True Believers seem totally incapable of understanding that circumstantial evidence can be as damning as direct evidence. Yet, somehow, they believe their own "evidence" for their own theory is better, even though they have neither direct evidence or compelling circumstantial evidence. They seem to just believe they are right, and they want the FBI to find the evidence that will prove them right.