Both knew or had met Mr. Trump during that period: Ms. Birnbach had recently interviewed him at Mar-a-Lago, his private club in Palm Beach, Fla., while Ms. Martin had met him at her news station and had a friend who briefly dated him.

■ When Ms. Carroll told the two women about the alleged attack, they had very different reactions: Ms. Birnbach said she told Ms. Carroll to call the police, while Ms. Martin told Ms. Carroll not to talk about it because Mr. Trump was too powerful. Ultimately, Ms. Carroll, thinking she was partially to blame for the encounter, remained silent about it for decades.

“I said: Don’t tell anybody. I wouldn’t tell anybody this,” Ms. Martin said.