The judge overseeing the sex-crimes trial of Harvey Weinstein on Thursday declared a mistrial on a final charge against him, after the jury foreman said he was unwilling to return to deliberations.

The ruling followed a wild day in court on Wednesday, in which jurors in Manhattan convicted Mr. Weinstein of a felony sex crime but were then sent home to cool off. The jury foreman had complained to the judge that deliberations had devolved into yelling and that he felt threatened by the other jurors.

On Wednesday, the panel of seven women and five men announced a partial verdict, convicting Mr. Weinstein on a single count of criminal sexual act and acquitting him of another count of the same charge. They were unable to reach a consensus on a charge of third-degree rape.

On Thursday, the foreman said he was not willing to return to the jury room and continue deliberating with the 11 others.

“I will declare a mistrial to the one count the jury has not decided,” the judge said.