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 morning, after the foreman said he was unwilling to continue, the judge thanked the jurors for their service and told them he was obligated to declare a mistrial on the remaining count.

“Sometimes jury deliberations become heated,” Justice Curtis Farber said. “I understand this particular deliberation was more heated than some others. That’s unfortunate.”

After releasing them, Justice Farber said he had spoken to the others on the jury, describing them as “extremely disappointed.” They did not, he said, describe the deliberations as contentious as the foreman had. “They did not describe anything that rose to the level of threats,” he said.