"Before the arraignment hearing, deputy marshals booked the former president and took electronic copies of his fingerprints. They did not take a mugshot of Trump since he is easily recognizable. The booking process took about 10 minutes."
https://www.cnn.com/2023/06/13/politics/trump-indictment-federal-court-appearance/index.html
@zacnewman They aren't legally required to read them anymore - SCOTUS ruling. The reason I said that is right to remain silent is for your own protection - in his case he is as much a threat to his freedom as the DOJ by making himself their best witness.
I also thought they did electronic scan of his fingerprints ( inkless)