Many of his accusers were bracing for an acquittal. Fellow prosecutors across the country were quietly questioning whether the New York district attorney, Cyrus R. Vance Jr., had made a mistake by bringing charges.

But by pushing the boundaries of sex-crimes prosecutions, the Manhattan prosecutors delivered what many people declared a victory for the global movement against sexual misconduct that Mr. Weinstein’s actions had helped ignite.

“It’s a perfect test case of what happens when a culture begins to shift,” said Deborah Tuerkheimer, a law professor at Northwestern.

Along the way, one accuser had to be dropped from the case amid allegations of police misconduct. The central victims acknowledged having had consensual sex with the Hollywood producer after being attacked by him, and one had an intimate relationship with him that stretched for several years. Prosecutors almost never try cases in those circumstances, deeming them too messy to win convictions. At every turn, Mr. Weinstein’s lawyers argued he was a victim of the #MeToo movement gone too far.

The jury’s verdict was ultimately mixed. Mr. Weinstein was acquitted of two counts of predatory sexual assault, the most serious charges against him. The jury had suggested on Friday that it was deadlocked on those counts.

“This wasn’t ‘Believe all women,’ and certainly not ‘Believe everything women are saying,’” said Isabelle Kirshner, a former Manhattan prosecutor turned criminal defense lawyer, who has represented men accused of sexual assault. “It looks like they were fairly careful on what they decided.”

But prosecutors persuaded the jury to convict on two felony sexual assault charges — which could send him to prison for up to 29 years — suggesting that accountability stretches from the court of public opinion to the court of criminal law.

On Monday, some of Mr. Weinstein’s more than 90 accusers, and others around the world, reacted to the verdict with relief, tears and gratitude that the law had spoken for them.

“For so long these women believed that he was untouchable and could never be held responsible, but now the criminal justice system has found him guilty,” said Tarana Burke, the founder of the #MeToo movement. “That sends a powerful message.”

The #MeToo movement helped propel the prosecution. Mr. Vance, the district attorney, had drawn criticism for failing to prosecute Mr. Weinstein in 2015 after an Italian model complained to the police that the producer had grabbed her breasts and tried to force his hand up her skirt. And some of Mr. Weinstein’s accusers who had not previously gone to the police were then willing to participate in the criminal justice process if it meant supporting and protecting other women.

“I just wanted to add my voice in support, and share my experience with the hopes of helping anyone else who was” victimized, Miriam Haley, a former production assistant, said on the witness stand.

“I did it for all of us,” Dawn Dunning, who served as a supporting witness in the trial, said in an interview on Monday. “I did it for the women who couldn’t testify. I couldn’t not do it.”

Joan Illuzzi, the lead prosecutor, did not have much by way of forensic evidence or direct witnesses to prove wrongdoing. Instead, her team strove to establish a pattern of predation, putting four additional women on the stand who told similar stories of rape or abuse by Mr. Weinstein. Those types of supporting witnesses had proved crucial in the successful prosecution of Bill Cosby in 2018. In the Weinstein trial, they provided testimony that was much larger than the sum of its parts, reflecting the collective power of women’s voices at the core of #MeToo.

For decades Mr. Weinstein used high-priced lawyers and secret settlements to silence women with allegations of sexual misconduct against him. But during the trial, which began in early January, he was the one who could not speak. On the advice of his lawyers, he did not take the stand. Instead, he listened as six women testified about what they said he had done to them.

Many of the women described being humiliated by the producer. As they spoke, Mr. Weinstein often appeared humiliated. At one point, as one accuser, Jessica Mann, described his genitals, Mr. Weinstein hung his head.

To counter the allegations, Mr. Weinstein and his legal team drummed home the message that #MeToo had spun out of control.

On the day of his arrest, he walked into a TriBeCa precinct house carrying a biography of Elia Kazan, the Hollywood director who became a victim of McCarthyism. He switched counsel several times, finally setting on Donna Rotunno, a Chicago lawyer who framed much of her defense as a broader attack on #MeToo. She argued that Mr. Weinstein’s sexual encounters were consensual, that his accusers were lying to achieve celebrity status, that women weren’t taking responsibility for their safety, and that men were the true victims and the movement had robbed them of their fundamental rights.

In an interview with “The Daily,” Ms. Rotunno asserted that she had never been a victim of sexual assault because she had never put herself “in that position.”

In her closing argument, she criticized what she said was “a universe that strips adult women of common sense, autonomy and responsibility.”

But the jury appears to have rejected those arguments. The Weinstein verdict could prove a symbolic turning point, legal experts said, showing that sex crimes don’t necessarily follow neat scripts and reshaping public beliefs about which victims deserve their day in court.

The verdict provides hope that we can “have a criminal justice system that reflects the reality of sexual violence,” said Fatima Goss Graves, the president of the National Women’s Law Center.

Mr. Weinstein’s legal team has already said it will appeal the convictions, of rape and criminal sexual act. The producer also faces a separate criminal prosecution in Los Angeles, where he has been charged with raping one woman and sexually assaulting another.

Jane Manning, a former Queens prosecutor and founder of the Women’s Equal Justice Project, said she hoped the Weinstein case would inspire other prosecutors around the country to pursue similarly challenging cases.

“That’s how to cultivate the skill set to try them successfully,” she said. “We need prosecutors to show courage.”