The GOP nominee, firing up a large crowd of loyal supporters during a swing through Florida, also laid into the Democratic nominee over her health and seized on disclosures from hacked emails of her campaign chairman, John Podesta, released by Wikileaks.
The broadsides came as Trump sought to get the focus back on his presidential rival, following a slump in his poll numbers triggered by his latest debate performance along with lewd and sexually aggressive remarks on a 2005 video that surfaced last week.
At a morning rally in Ocala, Trump said that he was "embarrassed" Congress had not done more to probe Clinton after the FBI decided not to seek charges against her over the private email server she used as secretary of state.
"Do they make deals like this?" Trump asked.
"This is the most heinous, the most serious thing that I've ever seen involving justice in the United States — in the history of the United States."
"We have a person that has committed crimes that is now running for the presidency."
Later on, after moving on to Lakeland, Florida, Trump again renewed his vow to appoint a special prosecutor to investigate Clinton if he is elected.
Clinton "has to go to jail," Trump warned, adding that the lawyers working for her over the email issue should also be incarcerated.
Trump also took a fresh shot at Clinton's health, saying that she would not, like him, be able to stand and deliver a raucous speech for an hour in a boiling hot livestock shed that was hosting his rally.
"Let Hillary Clinton stand up here for an hour and talk the way I talk, and let's see how long she lasts, folks," Trump said. "What a joke."
The Republican nominee also argued that emails released by Wikileaks showed Clinton had been "viciously attacking Catholics and evangelicals."
"That won't be tolerated. Anybody of religion, I really think you have to vote for Donald Trump to be honest with you," he said.
Trump was apparently referencing a 2011 email between John Podesta, the subject of the Wikileaks hack and Clinton's campaign chairman, communications director Jennifer Palmieri and John Halpin, a senior fellow at the liberal think-tank Center for American Progress.
In the email, Halpin writes that 21st Century Fox Chairman Rupert Murdoch and News Corp Chairman Robert Thomson, who are both Catholic, are attracted to the faith because of "systemic thought and severely backward gender relations."
Palmieri responded, "I imagine they think it the is the most socially acceptable, politically conservative religion -- their rich friends wouldn't understand if they became evangelical."
Palmieri told reporters Wednesday that she "didn't recognize (the email) but moreover... we are not going to fact check each of the emails that were stolen, hacked by (Russia) ... in an effort to hurt our campaign."