Last week, the F.B.I. took the extraordinary step of searching Mar-a-Lago, former President Donald J. Trump’s private club and Florida home. Their goal? To find materials he was thought to have improperly removed from the White House, including classified documents. An inventory of the material taken from the search showed that agents seized 11 sets of documents with some type of confidential or secret marking on them. We explore some of the latest developments in the case.