RE: Per FBI they only found 106 pages of interest to them.
Next question — how did they know Trump did not declassify them? Was there a written procedure a president needed to follow?
Any procedure is moot. As chief executive, Trump had the power to classify or declassify with or without procedure. Trump had the power to personally change or have someone else change any procedures. Trump had the power to declare documents to be presidential records. (That is key. The classification nonsense has nothing to do with this case.)
Trump did not have to notify anyone or seek approval from anyone to change procedures, for himself or anyone else in the executive branch. That includes determining which documents are presidential records. Congress and the judiciary do not have the power to usurp the President’s constitutional powers.
If you want to know what Trump was doing with documents while he was President, all you need to do is look at his actions, which are legal actions because there are no laws that can eliminate the President’s constitutional powers. If there are, then the law is unconstitutional.
All documents and information within the executive branch of government exist for the President’s benefit and for the President to do his job. All classification schemes are for the benefit of the President’s administration of government. No executive branch entity or employee has ANY authority over the President’s actions in regards to classification and whether the documents are presidential records.
When President Trump directed the GSA to pack and transport the documents to Mar-a-Lago he did so while in office and with his direction to do so it can be assumed that he was declaring the documents to be personal records of his administration of government. It should not be the default assumption that he was breaking the law when he had full powers to avoid breaking the law.
It is important to not conflate President Trump’s declassification of documents with anything to do with his own access to documents. For example, when Trump declassified the Crossfire Hurricane documents he did not do that for his access to the documents. He did it for other people’s access to the documents. Trump, while President, always had legal access to all documents within the executive branch. No one had the power to say ‘no’.