WASHINGTON — A former F.B.I. lawyer intends to plead guilty to falsifying a document as part of a deal with prosecutors conducting their own criminal inquiry of the Russia investigation, according to three people familiar with the case.
The lawyer, Kevin Clinesmith, 38, who was assigned to the Russia investigation, plans to admit that he altered an email from the C.I.A. that investigators relied on to seek renewed court permission in 2017 for a secret wiretap on the former Trump campaign adviser Carter Page, who had at times provided information to the spy agency. Mr. Clinesmith’s lawyers said he made a mistake while trying to clarify facts for a colleague, the people said.
Mr. Clinesmith had written texts expressing opposition to President Trump, who is sure to tout the plea agreement as evidence that the Russia investigation was illegitimate and politically motivated. Mr. Trump has long been blunt about seeing the continuing investigation by the prosecutor examining the earlier inquiry, John H. Durham, as political payback whose fruits he would like to see revealed in the weeks before the election.
Attorney General William P. Barr has portrayed Mr. Durham’s work as rectifying what he sees as injustices by officials who sought in 2016 to understand links between the Trump campaign and Russia’s covert operation to interfere in the election.
But prosecutors were not expected to reveal any evidence in charging documents that show Mr. Clinesmith’s actions were part of any broader conspiracy to undermine Mr. Trump, the people said. And the Justice Department’s independent inspector general, Michael E. Horowitz, has found that law enforcement officials had sufficient reason to open the Russia investigation, known inside the F.B.I. as Crossfire Hurricane, and found no evidence that they acted with political bias.
As part of their efforts to dissuade prosecutors from charging Mr. Clinesmith, his lawyers argued that his motives were benign, and other evidence indicated that he had not tried to hide the C.I.A. email from his colleagues, the people said.
Mr. Clinesmith was expected to be charged in federal court in Washington with a single felony count of making a false statement. He did not respond to an email seeking comment. A spokesman for Mr. Durham declined to comment.
Mr. Barr had previewed the agreement on Fox News’ “Hannity” on Thursday night, announcing that a development would occur in the investigation on Friday. “It’s not an earth-shattering development, but it is an indication that things are moving along at the proper pace, as dictated by the facts in this investigation,” he said.
It is highly unusual for law enforcement officials to publicly discuss ongoing investigations, but Mr. Barr has long made clear his distaste for the Russia investigation and his view that Mr. Durham would remedy any issues with it.
Though the sprawling Russia investigation that was eventually run by a special counsel, Robert S. Mueller III, uncovered the Kremlin’s complex operation to subvert the election and the Trump campaign’s expectation that it would benefit from foreign involvement, Republicans have seized on a narrow aspect of the inquiry — the investigation into Mr. Page — in a long-running quest to undermine it.
An energy executive with contacts in Russia, Mr. Page was brought on to advise the Trump campaign in the spring of 2016 as the candidate was solidifying his unexpected lead in the Republican primary race and scrambled to cobble together a foreign policy team.
Investigators eventually suspected that Russian spies had marked Mr. Page for recruitment. They first obtained permission from the secretive Foreign Intelligence Surveillance Court in October 2016 to wiretap him, and the court agreed to extend the order three times in subsequent months.
After Republicans raised concerns about the information that investigators relied on to seek the court’s approval to eavesdrop on Mr. Page, Mr. Horowitz began an exhaustive review of the process.
In a report made public last year, Mr. Horowitz revealed that the applications were riddled with serious errors and omissions. Among other things, he had learned of a troubling series of events in which Mr. Page’s association with the C.I.A. was not accurately conveyed to the Justice Department and ultimately kept from the judges who approved the surveillance warrants.
Mr. Page had for years provided information to the C.I.A. about his contacts with Russian officials. In C.I.A. jargon, he was known as an operational contact — someone who agrees to be debriefed by agency personnel but cannot be assigned to collect information.
That relationship might have given law enforcement officials reason to be less suspicious of him. And the F.B.I. was told about it: A C.I.A. lawyer provided a list of documents in the August 2016 email at the heart of the case against Mr. Clinesmith that explained Mr. Page’s relationship with the agency.
But an F.B.I. case agent who learned about Mr. Page’s ties to the C.I.A. played them down while preparing the first wiretap application, according to the inspector general’s report. At the time, Mr. Clinesmith was not involved in determining whether Mr. Page was a C.I.A. source, the people said.
But later in 2017, a supervisory F.B.I. agent handling the third and final renewal application asked Mr. Clinesmith for a definitive answer on whether Mr. Page had been an agency source, according to Mr. Horowitz’s report.
Mr. Clinesmith incorrectly said that Mr. Page was “never a source” and sent the C.I.A.’s information to the supervisor. He altered the original email to say that Mr. Page had not been a source — a material change to a document used in a federal investigation.
The agent relied on the altered email to submit the application seeking further court permission to wiretap Mr. Page, the inspector general wrote. By changing the email and then forwarding it, Mr. Clinesmith misrepresented the original content of the document, which prosecutors said was a crime.
Mr. Clinesmith did not change the document in an attempt to cover up the F.B.I.’s mistake, the people familiar with the case said. His lawyers argued that he had made the change in good faith because he did not think that Mr. Page had been an actual source for the C.I.A.
Mr. Clinesmith’s lawyers also argued that their client did not try to hide the C.I.A. email from other law enforcement officials as they sought the final renewal of the Page wiretap. Mr. Clinesmith had provided the unchanged C.I.A. email to Crossfire Hurricane agents and the Justice Department lawyer drafting the original wiretap application.
Mr. Clinesmith had also urged investigators to send any information about an informant’s meeting in October 2016 with Mr. Page, including any exculpatory statements, to the Justice Department lawyer drafting the wiretap application. Mr. Clinesmith said this was “probably the most important” information to provide to the lawyer drafting the wiretap application.
Mr. Clinesmith was among the F.B.I. officials whom Mr. Mueller removed from the Russia investigation after Mr. Horowitz found messages they had exchanged expressing political animus against Mr. Trump. Shortly after Mr. Trump’s election victory, Mr. Clinesmith texted another official: “I honestly feel like there is going to be a lot more gun issues, too, the crazies won finally. This is the tea party on steroids. And the GOP is going to be lost.”
In another text, he wrote, “viva le resistance.”
Mr. Clinesmith told the inspector general that he was expressing his personal views but did not let them affect his work.
Mr. Clinesmith also argued against the prospect of wiretapping another former Trump campaign adviser, George Papadopoulos, who served two weeks in jail on a charge of lying to the F.B.I., according to the Horowitz report. The inspector general said the bureau never sought to surveil him.
The prosecution of Mr. Clinesmith is just one aspect of Mr. Durham’s expansive investigation. He has also been examining the intelligence community’s most explosive conclusion about Russian interference in the 2016 election: that President Vladimir V. Putin intervened to benefit Mr. Trump.
Mr. Durham has also been scrutinizing the use of a notorious dossier in the wiretap applications that was compiled by a former British intelligence officer, Christopher Steele.
Mr. Durham, who has previously investigated F.B.I. and C.I.A. abuses, has not tipped his hand at what he has found, though Mr. Barr has said some of the findings are “troubling.” Mr. Durham has said in a rare statement that he disagreed with some of Mr. Horowitz’s conclusions about how and why the F.B.I. opened the inquiry in the summer of 2016.