In the end, because of legal issues surrounding Mr. Berman’s appointment, Mr. Barr was forced to ask Mr. Trump to fire him. He also backed away from his plan for temporary succession and installed Mr. Berman’s deputy, Audrey Strauss, to run the office for now.
Mr. Berman’s dismissal also came at a time when Mr. Trump had been pushing out other administration officials with a degree of independence, including inspectors general who are tasked with rooting out agency fraud and abuse.
On Thursday, Mr. Donoghue, the U.S. attorney in the Eastern District of New York, notified his office that he would be stepping down to become an official with the Justice Department in Washington, according to people familiar with the matter.
The post he will assume — principal associate deputy attorney general, working under Mr. Rosen — is considered extremely influential, as Mr. Rosen’s office oversees the nation’s federal prosecutors’ offices. A previous official in the role, Edward O’Callaghan, was best known for overseeing the day-to-day of the Russia investigation.
The job is particularly critical under Mr. Rosen, who has never been a prosecutor.
Mr. DuCharme, who is Mr. Rosen’s current top deputy, will return to the Brooklyn office, where he had worked for his entire career as a prosecutor before he came to Washington last year to advise Mr. Barr on criminal and national security matters.
Mr. Berman will testify just a week after two Justice Department lawyers told the House Judiciary Committee that political appointees in the prosecutor’s office in Washington and in the antitrust division had intervened in investigations to advance the personal interests of Mr. Trump and Mr. Barr.
Aaron S.J. Zelinsky, a prosecutor who worked on the investigation into Roger J. Stone Jr., Mr. Trump’s longtime friend, told the committee that senior officials in the Washington U.S. attorney’s office demanded a more lenient prison sentence for Mr. Stone “because of politics.”