When the National Archives asked for the documents, Trump ignored the request.
When the National Archives subpoenaed the documents, Trump handed over some but not all.
When the FBI got a tip with a description of more documents that remained and that Trump had withheld them, the FBI was justified in filing for a search warrant.
The search warrant is justified when all other recourse has been tried and failed.
And the proof was in the result - Trump was illegally holding onto government documents in violation of the Espionage Act; a law that does NOT depend on classification vs declassification.
Here's some commentary about Trump's "declassification" defense:
Mr. Bolton, who served as Mr. Trump’s third national security adviser over 17 months, said he had never heard of the standing order that Mr. Trump’s office claimed to have in place. It is, he said, “almost certainly a lie.”
“I was never briefed on any such order, procedure, policy when I came in,” Mr. Bolton said, adding that he had never been told of it while he was working there, and had never heard of such a thing after. “If he were to say something like that, you would have to memorialize that, so that people would know it existed,” he said.
What’s more, he pointed out, secure facilities for viewing sensitive material were constructed at Mr. Trump’s clubs in Florida and New Jersey, where he often spent weekends as president, meaning that the documents wouldn’t need to be declassified. And if they were declassified, Mr. Bolton said, they would be considered subject to public record requests.
He continued, “When somebody begins to concoct lies like this, it shows a real level of desperation.”
A bit more:
The claim that the documents held in the Florida residence were declassified also undercut an assertion one of Mr. Trump’s lawyers made in June. In a written declaration, the lawyer’s team said all material marked as classified and stored at Mar-a-Lago had been returned to the government.
