NEW YORK (AP) — Lawyers for a woman who accuses President Donald Trump of raping her in the 1990s are asking for a DNA sample, seeking to determine whether his genetic material is on a dress she says she wore during the encounter.

Advice columnist E. Jean Carroll’s lawyers served notice to a Trump attorney Thursday for Trump to submit a sample on March 2 in Washington for “analysis and comparison against unidentified male DNA present on the dress.”

Carroll filed a defamation suit against Trump in November after the president denied her allegation, saying he didn’t know and had never even met her. Her lawyer, Roberta Kaplan, then had the black wool coat-style dress tested. A lab report with the legal notice says DNA found in skin cells on the outer surface of the sleeves was a mix of at least four people, at least one of them male.

Several other people were tested and eliminated as possible contributors to the mix, according to the lab report, which was obtained by The Associated Press. Their names are redacted, but the report indicates they were involved in a photo shoot where she wore the dress last year, the only time Carroll says she has donned the dress since the alleged assault.

“Unidentified male DNA on the dress could prove that Donald Trump not only knows who I am, but also that he violently assaulted me in a dressing room at Bergdorf Goodman and then defamed me by lying about it and impugning my character,” Carroll said in a statement Thursday.

The White House and Trump’s lawyer have not responded to a request for comment.

While the notice is a demand, such demands sometimes spur court fights requiring a judge to weigh in on whether they will be enforced.

Carroll accused Trump last summer of raping her in a dressing room in Bergdorf Goodman, a Manhattan luxury department store, in the mid-1990s.

In a New York magazine piece in June and a book published the next month, Carroll said she and Trump met by chance, chatted and went to the lingerie department for Trump to pick out a gift for an unidentified woman. She said joking banter about trying on a bodysuit ended in a dressing room, where she said Trump pinned her against the wall by her arms, reached under the dress, pulled down her tights and raped her as she tried to fight him off, eventually escaping.

“The Donna Karan coatdress still hangs on the back of my closet door, unworn and unlaundered since that evening,” she wrote. She donned it for a photo accompanying the magazine piece.

She had kept the dress because it was a favorite and she hoped she could someday feel comfortable wearing it again, her legal team says.

Trump said in June that Carroll was “totally lying” and he had “never met this person in my life.” While a 1987 photo shows them and their then-spouses at a social event, Trump dismissed it as a moment when he was “standing with my coat on in a line.”

“She is trying to sell a new book — that should indicate her motivation,” he said in one of various statements on the matter, adding that the book “should be sold in the fiction section.”

Carroll sued Trump in November, saying he smeared her and hurt her career as a longtime Elle magazine advice columnist by calling her a liar. She is seeking unspecified damages and a retraction of Trump’s statements.

Her lawyer, Kaplan, said the DNA sample request was “standard operating procedure” given the unidentified male DNA on the garment.

“As a result, we’ve requested a simple saliva sample from Mr. Trump to test his DNA, and there really is no valid basis for him to object,” she said.

Trump’s lawyer has tried to get the case thrown out. A Manhattan judge declined to do so earlier this month, saying the attorney hadn’t properly backed up his arguments that the case didn’t belong in a New York court.

The Associated Press typically does not name people who say they have been sexually assaulted, unless they come forward publicly.

Carroll said she didn’t do so for decades because she feared legal retribution from Trump and damage to her reputation, among other reasons. But when the #MeToo movement spurred reader requests for advice about sexual assault, she said, she decided she had to disclose her own account.

Trump, a Republican, isn’t the first president to face the prospect of a DNA test related to a woman’s dress.

Former President Bill Clinton, a Democrat, underwent such a test during an independent counsel investigation into whether he had a sexual relationship with onetime White House intern Monica Lewinsky and then lied in denying it under oath.

After Clinton’s DNA was found on the dress, he acknowledged an “inappropriate intimate relationship” with Lewinsky.

Clinton was impeached by the House in December 1998 and later acquitted by the Senate.