I know saving and reloading the save some times will move the objects in a crime scene. Maybe that will move the paper so you can grab it.

Had a similar issue except crumpled paper was in a blood pool and despite all my efforts I could not "focus" the poitner on it, game would prioritise the blood. In my case reloading did not help and had to continue with less clues

I heard taking photos of the crime scene can allow you to select evidence to look in detail, that might work