US election: Trump launches ferocious attack on Clintons
The Republican nominee denied ever sexually assaulting women, but turned his fire on ex-President Bill Clinton in a bitter US presidential debate.
"There's never been anybody in the history of politics that has been so abusive to women," he said.
Hillary Clinton refused to address his comments about her husband.
Mr Trump's attack on the Clintons came after moderator Anderson Cooper asked him about a 2005 video recording released on Friday that revealed Mr Trump bragging about groping women.
But when pressed on whether he had engaged in sexual misconduct with any women, he denied doing so and instead focused on Mr Clinton's previous indiscretions.
No criminal charges have been brought against Mr Clinton in any allegations of sexual assault.
Mrs Clinton said the explosive video, which has sparked an exodus of Republicans denying support to their presidential nominee, showed who Mr Trump really was.
"With prior Republican nominees, I disagreed with them," she added, "but I never questioned their fitness to serve.
"I think it's clear to anyone who heard [the video] that it represents exactly who he is."
When the two took to the stage in St Louis for their second of three debates, they did not shake hands, striking a bitter tone that would continue throughout.
Mr Trump said if he won, he would appoint a special prosecutor to investigate Mrs Clinton and she would be in prison over her private email arrangements.
"Everything he just said is absolutely false but I'm not surprised," she responded. "It's just awfully good that someone with the temperament of Donald Trump is not in charge of the law in our country."
"Because you'd be in jail," he interrupted.
Mr Trump also said his Democratic rival "has tremendous hate in her heart" while criticising her for referring to his supporters as "deplorables".
Mrs Clinton said she apologised for the comment, adding: "My argument is not with his supporters, it's with him, about the hateful and divisive campaign he has run."
The two also sparred on the conflict in Syria, Russian aggression, Trump's refusal to release his tax returns and his plan for the "extreme vetting" of immigrants arriving from countries with links to terrorism.
The evening concluded when an audience member asked the candidates to say one positive thing about each other.
Mrs Clinton said his children were a great reflection of him while Mr Trump called his opponent "a fighter" who never gives up.
An hour before the debate began, Mr Trump appeared at a press conference with women who accused Bill Clinton of sexual misconduct.
He joined three women who allege the former president sexually assaulted them and called the women "very courageous".
The Republican was under immense pressure after making obscene comments about women in the video.
At least 33 senior Republicans - including senators, members of Congress, and state governors - have withdrawn their support since the video surfaced on Friday.
Source: bbc.com