Subject: Re: Robert Hur and the Biden documents case
So even if - at a time before being asked to return them - Biden knew he had those Afghanistan documents - and kept them as a private citizen - he had returned them all when asked to, he wouldn't have committed a crime?

As far as I know, yes. As long as they came into his possession legally (which it appears they did), it's not a crime for him simply to possess them. But it is a crime for him to refuse to return them.

That's why the Trump and Biden cases differ. Trump's issues don't stem from having the documents in the first place - they stem from refusing to give them back and then trying to conceal the fact that he kept them.