It is up to a jury to determine the facts based only on the evidence that is admitted in the courtroom. No one can tell them how much weight to assign to any evidence. The probative evidence of a fact in question can be more than one piece of evidence. The weights can be combined such that the probability is very high. And if there isn’t any compelling opposing evidence, the fact in question can be concluded to be beyond a reasonable doubt. But all of that is completely up to the jury.
Here's a photo of some of the classified documents found at Trump's home/residence/Mar-a-Lago. Is it really his residence? It possibly could be another place. Are they really classified documents? It possibly could be innocuous/personal material and not secrets. Is the photo real? Not faked? It possibly could be faked or photo shopped. Are the documents the ones requested by the government, by the National Archives? They may be different ones.
We could speculate again and again about the evidence here. About the photo and its authenticity and what it shows. But we have more than just the photo. We have a record that shows that Trump kept classified documents. And he stored them at Mar-a-Lago. And in a bathroom/unsecured place. If all you use is this photo - and speculate about it and say there's a *possibility* it's faked - then the evidence can be made to disappear. Trump didn't illegally keep classified materials because the evidence is just speculation and claims. The evidence could be this or that, the evidence could be faked, it could be staged. Do this for each piece. Presto, it disappears.
This is how the Oswald defenders look at the evidence. They characterize it as speculation, as possibly being corrupt or not authentic (obviously, many say
it is corrupt and faked), and then wave it away. And *then* ignore the corroborating evidence. Which is also isolated and dismissed as speculation as well. This is not how you reconstruct an event, at how you look at one. You look at the totality of evidence and reconstruct what happened.