Transcript for Department of Justice intervenes in lawsuit against Trump
much. To Washington now where the justice department has made an extraordinary move in a defamation suit against president trump. The suit comes from a woman who claims trump raped her in the 1990s and now the justice department is taking on the case asserting that the president was acting in his official capacity when denying the allegation. Senior white house correspondent Cecilia Vega has the story and this means taxpayers will pay for his defense. Reporter: Exactly and they might have to pick up the bill for any legal settlement. They failed to delay the lawsuit. The president had been on the verge of having to sit for a deposition. That is, until the justice department stepped in. This morning, an unprecedented move by the justice department stepping in to replace president trump's private legal team to represent him in a high-profile defamation lawsuit and means American taxpayers would foot the bill for the government defending the president in the suit by author E. Jean Carroll who says the president raped her more than two decades ago in a dressing room at Bergdorf Goodman's. Walked in at the minute I was in there, he shut the door and pushed me up against the wall and, bang, banged my head on the wall and kissed me. I just -- it was so shocking. Reporter: The president denied the allegations telling the hill, quote, she's not my I have no idea who she is, none whatsoever. Reporter: With just 55 days to go until the election the latest move protects the president from any potentially embarrassing disclosures. Carroll's lawyers requested the president provide a DNA sample to determine whether a dress she was wearing at the time of the alleged assault matches his DNA. Justice department lawyers argue because he was acting within the scope of his office at the time of his denial, he could be defended by government attorneys. Carroll said the president will do everything possible including using the full powers of the federal government to block discovery from going forward in my case. But trump underestimates me and he also has underestimated the American people. Now, president trump has been accused of sexual misconduct by more than a dozen women. Critics say this is just the latest example of bill Barr acting as the president's attorney rather than America's attorney general. E. Jean Carroll tweeted, president trump sics bill Barr against her. Next week I will anchor a town hall for a special edition of "20/20" "The president and the people: A national conversation" Tuesday, September 15th at 9:00 eastern.
This transcript has been automatically generated and may not be 100% accurate.