(CNN)Donald Trump was on his heels like never before after audio of a lewd and sexually aggressive comments he made in 2005 surfaced on Friday. Hillary Clinton sought to maintain her lead in the race and will be on defense against Trump.
Reality Check Quick Takes: Can Trump appoint a special prosecutor to investigate Clinton?
Sunday's debate in St. Louis was dramatic, to say the least. Here's the fact-check, as it happened:
Can Trump appoint a special prosecutor to investigate Clinton?
Trump said "If I win, I am going to instruct my Attorney General to get a special prosecutor to look into your situation because there has never been so many lies, so much deception."
The US Attorney General does have the authority to appoint a special prosecutor, according to Stephen Vladeck, a CNN legal contributor and law professor with the University of Texas School of Law. Such action can be taken when the Attorney General determines that a criminal investigation is warranted and that an investigation by the Department of Justice would present a conflict of interest or "other extraordinary circumstance" and that "under the circumstances it would be in the public interest to appoint and outside Special Counsel."
Trump: I didn't say "check out the sex tape"
Tweeting at 5 a.m. amid allegations that he called former Miss Universe Alicia Machado "Miss Piggy" -- which Trump didn't deny - the Republican nominee urged his Twitter followers to "check out [Machado's] sex tape and past."
Clinton: Trump has incited violence at rallies
Trump has said himself that he wanted to "punch him in the face," referring to a protester at his rally in February. And during another rally that month he urged: "If you see somebody getting ready to throw a tomato, knock the crap out of them, would you?"
Trump: "I would not have had our people in Iraq."
Trump was on the record as supportive of the Iraq War as early as a month before Congress voted to authorize military force in Iraq and even soon after the invasion. He didn't express his outright opposition to the war until more than a year later, in an August 2004 interview.
Trump: My opposition to the Iraq War "has not been debunked"
Trump's claim that he opposed the Iraq War has been repeatedly debunked by fact-checkers. He offered support for the invasion a month before Congress voted to authorize military force. And he praised the invasion soon after it launched. He didn't express his outright opposition to the war until more than a year later.
Trump: Clinton called TPP "gold standard"
Clinton said in 2012, as Secretary of State, that the Trans-Pacific Partnership deal "sets the gold standard in trade agreements." The trade deal wasn't yet finalized, and Clinton has since said she opposes the deal.
Trump claims Clinton campaign source of Obama photo in Somali garb
VERDICT: IT'S COMPLICATED
Trump told Clinton that "your campaign" was responsible for circulating photos during the 2008 primaries depicting Barack Obama dressed in traditional Somali garb, a famous flare-up during the Democratic primary eight years ago.
Well, sort of.
The photo first appeared on the conservative aggregator, the Drudge Report, and was attributed at the time to sources within the Clinton campaign, though no names were offered.
Clinton's campaign pointed the finger at a "volunteer coordinator" in Iowa who shared the photo, which was part of what Trump said was an effort to discredit Obama's heritage and legitimacy. It's not certain whether the volunteer was drawing a paycheck from her campaign and therefore an official Clinton actor.
Clinton: Trump didn't apologize for insulting comments
Clinton argued that Trump never apologized for attacking the parents of a slain US soldier; for calling a judge "biased against him" because of his Mexican heritage; for mocking a disabled reporter; and for questioning President Barack Obama's birthplace. Trump never apologized for any of those statements.
Quick take: Obamacare costs rise
VERDICT: TRUE, BUT MISLEADING
It's true that some insurers are raising some of their plans' premiums by "68%, 59%, 71%," but that's not the typical increase. Insurers have requested a rate hike of 9%, on average, for the benchmark Silver plan for 2017, up from 2% for this year, according to the Kaiser Family Foundation.
The vast majority of Obamacare enrollees, however, don't see those massive hikes. Some 85% of them receive federal subsidies that can lower their premium to less than 10% of their income.
Trump: "Many people saw the bombs all over the apartment"
Trump has repeatedly claimed that acquaintances of the San Bernardino terrorists saw "bombs all over" the shooter's apartment, as he did on Sunday night. There is no evidence to support that claim.
Trump: Clinton didn't know what "C" meant
Clinton told the FBI during her interview over her use of a private email server that she did not know what the "C" marking meant on classified documents. "C" means "Confidential."
Trump says US is giving $150 billion to Iran
Trump argued that the United States is giving $150 billion to Iran, suggesting that the US is making a lump sum payment to the country as a term of the nuclear deal. The US did not make a multibillion-dollar lump sum payment to Iran, instead freeing up about $50 billion in previously unfrozen Iranian assets, according to a White House estimate.