Mr. Weinstein, who was at the defense table for about two hours, was dealt a setback: His lawyers were told they could not call as a witness a detective who was accused of withholding evidence from prosecutors that was favorable to the defense.

“He dropped his head in his hands in what appeared to be disappointment,” Ms. Ransom said, referring to Mr. Weinstein’s reaction to the judge’s ruling.

Outside the courtroom

Protesters and curious New Yorkers, as well as several of Mr. Weinstein’s accusers, waited in the cold outside of the courthouse, hoping to look him in the eye, my colleagues Jodi Kantor and Emily Palmer said. Many later moved to Foley Square, two blocks from the building, for a news conference.

“I wish he would have turned around and faced us,” said the actress Rosanna Arquette, who had accused Mr. Weinstein of sexual harassment dating to the early 1990s.

Rose McGowan, an actress who has accused him of sexual assault, called the trial “a moment of justice,” even though most of his accusers “won’t have even one day in court.”

The case

Mr. Weinstein is charged with raping one woman, who has not been identified in court documents, at a Midtown hotel in 2013 and forcing a second woman, Mimi Haleyi, to allow him to perform oral sex on her at his Manhattan apartment in 2006.

He faces one count of rape and one count of criminal sexual act in those cases and, if convicted, could be sentenced to a maximum of 25 years in prison.