Rod J. Rosenstein, shown at a news conference this week in Baltimore, is poised to oversee the FBI’s investigation into Russian meddling in the 2016 election and any links between Russian officials and Donald Trump’s associates. (Patrick Semansky/AP)

When former attorney general Eric H. Holder Jr. came under fire for leaks of classified information about the Obama administration’s role in authorizing cyberattacks against Iran, he turned to a veteran federal prosecutor — a Republican — to help head his investigation into who was leaking.

That same federal prosecutor, Rod J. Rosenstein, is being tapped again, this time by President Trump’s attorney general, to oversee another high-profile case, the FBI’s investigation into Russian meddling and any links between Russian officials and Trump’s associates.

Attorney General Jeff Sessions recused himself Thursday from the investigation and designated his acting deputy attorney general, the second-highest-ranking official in the Justice Department, to oversee the probe. But the responsibility is expected to soon fall to Rosenstein, 52, the longest-serving U.S. attorney, whose Senate confirmation hearing to become deputy attorney general is set for Tuesday.

[Attorney General Jeff Sessions will recuse himself from any probe related to 2016 presidential campaign]

Rosenstein, the sole holdover U.S. attorney from the George W. Bush administration, is widely respected by Democrats and Republicans for his experience working on sensitive cases in the face of political pressure, according to attorneys he has worked with during his nearly three decades in the department.

(Peter Stevenson/The Washington Post)

“I cannot imagine a more challenging environment in which to be the deputy attorney general than what we have now,” said Jason M. Weinstein, a former Justice Department official who worked with Rosenstein during the administrations of Bush and Obama. “And I cannot imagine a better person for the job at this time than Rod. He is not political at all. In every decision he makes — and I’ve seen him make some very difficult ones — the only question he really cares about is what is right and what is just.”

A Philadelphia native, Rosenstein began working as a trial attorney in the public integrity section of President George H.W. Bush’s Justice Department after graduating from Harvard Law School, where he was an editor of the Harvard Law Review, and clerking for Judge Douglas H. Ginsburg of the U.S. Court of Appeals for the District of Columbia Circuit.

Soon afterward, President Clinton’s deputy attorney general hired Rosenstein to be his counsel. During the Clinton administration, Kenneth W. Starr tapped him to be his associate independent counsel on the investigation into the business dealings of the Clintons and their associates in the Whitewater Development Corp.

Rosenstein stayed on into the George W. Bush administration and in 2005, Bush appointed him U.S. attorney for the U.S. District Court for the District of Maryland, where he remained through the Obama administration.

“He came in under one administration, stayed under another and is now being elevated under yet another,” said George J. Terwilliger III, the former deputy attorney general and acting attorney general under George H.W. Bush. “That tells you everything about the consummate professional that he is.”

Beneath Rosenstein’s mild-mannered demeanor is a tough determination, his current and former colleagues say. As the Baltimore U.S. attorney, for example, Rosenstein successfully prosecuted then-Prince George’s County executive Jack Johnson for corruption.

Johnson was sentenced to seven years in prison in 2011 after an investigation in which he was heard on a wiretap ordering his wife, Leslie, to flush a $100,000 check from a developer down the toilet and hide $79,600 in cash in her underwear as FBI agents were knocking on their door with a search warrant.

(Jorge Ribas,Ashleigh Joplin/The Washington Post)

Earlier this week, Rosenstein announced indictments against seven Baltimore police officers in a racketeering conspiracy.

Rosenstein is also credited with turning around a troubled U.S. attorney’s office.

“He’s calm, deliberative, analytical and — as they used to say on the kindergarten report card — he works and plays well with others,” said former attorney general Michael Mukasey.

It was that reputation that led Holder to tap Rosenstein in 2012 to be one of two U.S. attorneys to oversee the investigations into the leaking of classified national security information. The probe resulted in the former vice chairman of the Joint Chiefs of Staff, Gen. James “Hoss” Cartwright, to plead guilty to one felony count of lying to the FBI.

“He ran that investigation effectively, vigorously and without any respect for partisanship,” said Robert S. Litt, former general counsel of the Office of the Director of National Intelligence in the Obama administration. “After all, he was going after the guy who was reported in the press to be Obama’s favorite general at a time when Obama was president.”

If he is confirmed, Rosenstein — who lives with his wife, an attorney, and two teenage daughters in Bethesda — will be responsible for the day-to-day running of the sprawling Justice Department, which has 113,000 employees across the country. The heads of the FBI, the Drug Enforcement Administration and the Bureau of Alcohol, Tobacco, Firearms and Explosives will report directly to him.

And as of Thursday, he will also take on the oversight of all federal investigations into Russia and the 2016 presidential election.

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