"I am sure a lot of you may be asking what this new email story is about and why in the world the FBI would decide to jump into an election with no evidence of any wrong doing with just days to go," Clinton said. "That is a good question."
The Democratic Party's presidential nominee added she felt confident that the FBI would reach the "same conclusion" as before: "There is no case here."
As she has in the past, Clinton also said it was a "mistake" for her to use a private server during her tenure at the State Department.
The comments at Kent State University marked Clinton's most aggressive remarks yet since FBI Director James Comey told congressional leaders Friday that the bureau has uncovered new emails that might be pertinent to Clinton's use of a private email server while she was secretary of state.
Those emails came to light during the FBI's probe
into Clinton aide Huma Abdein's estranged husband, Anthony Weiner, who allegedly exchanged sexually explicit messages with a 15-year-old.
Donald Trump and his fellow Republicans have latched on to Comey's announcement, pointing to it as evidence that the Democratic nominee is corrupt and not trustworthy.
Caught off guard by the development, Clinton and her aides have fiercely objected to the timing of Comney's action, and ramped up pressure on him swiftly release more information about what is contained in the emails.
"It's pretty strange to put something like that out with such little information right before an election," Clinton said in Florida over the weekend.
And just eight days out from Election Day, Clinton insisted Monday voters will not be swayed by Comey's announcement.
"I think most people have decided a long time ago what they think about all this," she said. "Now, what people are focused on is choosing the next president and commander in chief of the United States of America."
Clinton also forcefully told the audience on Monday in Ohio that the FBI "said it wasn't even a close call" on their decision not to go forward with their investigation into her email in July.
Clinton's campaign later cited an internal memo Comey sent to employees as proof.
"At the end of the day, the case itself was not a cliff-hanger; despite all the chest-beating by people no longer in government, there really wasn't a prosecutable case," he said in the memo