Attorney General Merrick Garland has assigned the U.S. attorney in Chicago to review classified documents found at the Penn Biden Center for Diplomacy and Global Engagement in Washington, two sources with knowledge of the inquiry told CBS News. The roughly 10 documents are from President Biden’s vice-presidential office at the center, the sources said.

The classified material was identified by personal attorneys for Mr. Biden on Nov. 2, the day before the midterm elections, Richard Sauber, special counsel to the president confirmed. The documents were discovered when Mr. Biden’s personal attorneys “were packing files housed in a locked closet to prepare to vacate office space at the Penn Biden Center in Washington, D.C.,” Sauber said in a statement to CBS News. The documents were contained in a folder that was in a box with other unclassified papers, the sources said. The sources revealed neither what the classified documents contain nor their level of classification. A source familiar told CBS News the documents did not contain nuclear secrets.

Sauber also said that on the same day the material was discovered, Nov. 2, the White House counsel’s office notified the National Archives, which took possession of the materials the following morning.

[And yet we’re only finding out about this now, two months after the midterm election. Why is that? — Ed]