Prosecutors overseeing the documents investigation have also been asking witnesses questions about Boris Epshteyn, who has played a central role in coordinating lawyers on several of the investigations involving Mr. Trump, according to multiple people briefed on the matter. It was Mr. Epshteyn who first brought Mr. Corcoran into Mr. Trump’s orbit.
At least three lawyers have sat for interviews with the Justice Department during which questions about Mr. Epshteyn were asked — among them Ms. Bobb and, more recently, Alina Habba, people with knowledge of the matter said. A third lawyer close to Mr. Trump, Jesse Binnall, has also spoken with prosecutors about Mr. Epshteyn, the people said.
One person briefed on the interviews said that investigators were interested in discussions between Mr. Epshteyn and others about establishing a possible common-interest privilege in the documents case. A common-interest privilege creates a kind of umbrella privilege allowing groups of lawyers and clients to communicate with each other confidentially.
Such common-interest agreements are typical in cases with multiple lawyers and multiple witnesses. But prosecutors are asking questions indicating they’re interested in whether Mr. Epshteyn was trying to influence witness testimony, the person briefed on the interviews said.
Mr. Binnall declined to comment.
Lawyers representing or advising Mr. Trump have been central players in both the documents and Jan. 6 investigations.
A federal judge in California issued an opinion in a civil case last year arguing that there was reasonable evidence that Mr. Trump and another one of his lawyers, John Eastman, had conspired together to commit at least two crimes in their efforts to overturn the results of the 2020 election: conspiracy to defraud the United States and obstruction of an official proceeding before Congress.
Mr. Eastman had filed a lawsuit seeking to prevent the House select committee investigating Jan. 6 from obtaining some of his emails by arguing that many were protected by attorney-client privilege. But the judge, David O. Carter, overruled him, citing the crime-fraud exception as a reason to allow the committee to have the emails.
In June, federal agents armed with a search warrant seized Mr. Eastman’s phone in connection with the Jan. 6 investigation.
William K. Rashbaum and Jonah E. Bromwich contributed reporting.
