The autopen is used to sign letters to people

"With the autopen, how would that work? Like, if we were in the Oval Office right now—if there were a group of rogue staffers working for you who wanted to pass a law or an executive order without your knowledge, how could they do it?

How would I find out? I’d read your newspapers or the media the next day and say, well, I didn’t approve that—and I’d look into it. I mean, they wouldn’t get away with it for long because I’d say: I didn’t sign that. Who the hell signed that?

Autopens, to me, are used to sign letters to people, because we get—I think they said—20,000 letters a week, and you like to be able to respond when someone takes the time to write a letter. And autopens are made for that.

Autopens are not meant for signing major proclamations or tax cuts, or matters related to the border, which is so important. And if that happened under my administration, I would know, because the next day—or before—I’d be reading about something I had no idea about. And who the hell signed this?

So I almost never used the autopen."

During Joe Biden's administration, controversies arose over the use of the autopen—a mechanical device that replicates signatures—for signing official documents, including presidential pardons. Critics, such as the Heritage Foundation’s Oversight Project, claimed that many documents signed by Biden featured identical signatures, suggesting extensive use of the autopen and raising questions about whether Biden personally authorized these actions.

These concerns intensified when it was discovered that some documents were marked as signed in Washington on dates when Biden was in other locations. Additionally, it was noted that the signature on his letter announcing his withdrawal from the 2024 presidential race differed from signatures on previous documents, suggesting it was signed manually—unlike the others.

In response, the Donald Trump administration launched an investigation to determine whether Biden was mentally competent to issue these pardons and whether he was aware of the use of the autopen. The investigation focused particularly on pardons granted to members of his family, including his son Hunter Biden, and to 37 federal inmates sentenced to death.