Judge James Burke's ruling buoyed a prosecution that appeared on rocky ground in recent months amid a prolonged defense effort to raise doubts about the case and the police investigation.
It was also welcome news for the #MeToo movement, which took off last year after numerous women accused Weinstein of wrongdoing. About a half-dozen women, including actress Marisa Tomei, showed up to court wearing t-shirts from the anti-abuse organization Time's Up.
Weinstein's lawyers argued the case had been "irreparably tainted" by a detective's alleged coaching of a potential witness and one of the accusers. They also said the grand jury that indicted Weinstein should have been shown friendly emails he exchanged with his two accusers after the alleged attacks.
But Burke ruled that Weinstein's prosecutorial misconduct claims had "no basis" and that prosecutors were under no obligation to give the grand jury evidence favorable to the defense. He denied Weinstein's demand for a hearing to examine the police investigation and rebuked his lawyers for what he said were "speculative" claims that political pressure had led to the charges.
"This court has found the grand jury presentation to be legally sufficient to support the charges and that the proceedings were properly conducted," Burke wrote in a six-page opinion detailing his decision. "Dismissal is an exceptional remedy and only available in rare cases."
Weinstein, 66, has denied all allegations of nonconsensual sex. He is free on $1 million bail and left court without commenting. His next court appearance is scheduled for March 7.
Weinstein's lawyer Benjamin Brafman said he was disappointed with the ruling but remains confident the former film producer will be "completely exonerated" at trial, which has not been scheduled.
"We intend to continue to vigorously defend this case to the best of our ability," Brafman told reporters after the hearing. He said that Burke's ruling "does not in any way suggest that the case against Mr. Weinstein is going to end badly."
The Manhattan District Attorney's office declined to comment.
Weinstein is charged with raping an unidentified female acquaintance in a hotel room in 2013 and performing a forcible sex act on a different woman in 2006. That woman's lawyer, Gloria Allred, lauded Burke's ruling, telling reporters afterward: "Mr. Weinstein shout have his day in court but so should the two women who are alleged to be the victims."
The Associated Press does not typically identify people who say they are victims of sexual assault unless they grant permission.
Images of Weinstein in handcuffs last spring were seen by many women as a cathartic moment in the #MeToo reckoning, but the case against him appeared to wobble in recent months with allegations of police misconduct and the defense's contention that they had evidence showing Weinstein's relationships with his accusers were consensual.
Prosecutors dropped part of the case in October — an allegation that Weinstein forced an aspiring actress to perform oral sex — when evidence surfaced that Detective Nicholas DiGaudio instructed one potential witness to keep doubts about the veracity of the allegations to herself.
But Burke noted in his ruling that the charge was dismissed because prosecutors determined they may not have been able to prove it, not because they thought she lied.
With the rest of the case up in the air, Thursday's hearing attracted extra attention. Dozens of reporters squeezed into the courtroom alongside Tomei, actress Amber Tamblyn and other celebrities there to support the accusers, while TV cameras filled the sidewalk outside.
"Today, here in New York, we saw the first steps towards justice," Time's Up President Lisa Borders said after the judge's ruling. "Frankly, we are relieved that Harvey Weinstein failed in his efforts to avoid accountability for his actions."
Had Burke tossed the case, it would have been a major setback for District Attorney Cyrus Vance Jr., who faced sharp criticism for declining to pursue criminal charges when Weinstein was accused of groping an Italian model in 2015. Vance cited a lack of supporting evidence, despite a clandestine recording of Weinstein discussing the episode with the woman.
Burke's ruling to move the case forward isn't necessarily bad for Weinstein, either, because his lawyers will still have an opportunity to raise doubts about the case with the jury, former New York prosecutor Adam Citron said.
Weinstein's lawyers have indicated that part of their defense will include a witness who will say Weinstein and the woman accusing him of rape had been "hooking up" for a while. They've also plucked emails from his movie studio's servers they say showed Weinstein had friendly, consensual relationships with both women.
"It doesn't mean they can't raise these claims at trial," said Citron, senior counsel with the New York firm Davidoff, Hutcher & Citron. "If anything, it may help the defense given the amount of media attention."
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This story has been corrected to indicate that the charge against Weinstein that was dropped in October involved an allegation that he forced a woman to perform oral sex, not a rape charge.