Mark Meadows, a former White House chief of staff, has been fighting to avoid testifying about efforts to keep former President Donald J. Trump in power after he lost the 2020 election.
The former president exhibited a pattern of dissembling about the material he took from the White House, creating legal risk not just for himself but also some of his lawyers.
In a closed-door interview with the House committee investigating the Jan. 6 attack, Ms. Thomas reiterated her false assertion that the 2020 election was stolen from President Donald J. Trump.
A lawyer representing the former president told the National Archives that boxes taken from the White House contained material like newspaper clippings.