WASHINGTON — In a stunning last-minute announcement, FBI director James Comey said Sunday that his agency's review of newly discovered emails has not altered his earlier conclusion that Democratic presidential nominee Hillary Clinton should not be prosecuted for her handling of classified information over email as secretary of State.

In a letter to lawmakers, Comey said the FBI is standing by its original findings made in July.

"The FBI investigative team has been working around the clock to process and review a large volume of emails from a device obtained in connection with an unrelated criminal investigation," Comey said in the letter. "During that process we reviewed all of the communications that were to or from Hillary Clinton while she was Secretary of State. Based on our review, we have not changed our conclusions that we expressed in July with respect to Secretary Clinton."

On Twitter, Clinton spokesman Brian Fallon said the campaign was "always confident nothing would cause the July decision to be revisited."

Comey had rocked the presidential race with his announcement Oct. 28 that the FBI had uncovered a new trove of emails that might be relevent to the investigation of Clinton's use of a private email server.