If he approved categories there should be a document with his real signature authorizing the auto-pen to be used on pardons/commutations for people falling with these certain categories. In lieu of that we can safely assume he did not know who he pardoned after 10:00 PM at night.No way he could stay up past 10...but that being said...
https://www.axios.com/2025/07/14/biden-defends-autopen-use-white-house. He may have approved categories at one point...though I doubt even that is true....