Former Deputy Attorney General Rod Rosenstein considered sneaking out of the White House a copy of President Trump's draft letter firing FBI Director James Comey in May 2017.

That four-page letter was never used, and in fact Rosenstein himself wrote a distinctly different memo used to justify Comey's termination, but the previously unreported account adds further details about the tumultuous experience the Justice Department's No. 2 official had over a span of several days which led up to the appointment of Robert Mueller to be special counsel of the investigation into Russian interference in the 2016 election.

The existence of the initial draft letter was first reported by the New York Times in September 2017 and only a portion of the letter, which was provided to Mueller's team, was conveyed in the special counsel's final report. But a report by the New York Review of Books on Wednesday sheds new light on the contents of that draft letter and Rosenstein's actions in May 2017.

In the draft letter, Trump made clear he wanted to fire Comey because of the Russia investigation and his frustration with the director refusing to say publicly that Trump was not personally under investigation.

Also among the previously unreported aspects of the draft letter was Trump's dismay with Comey allowing FBI Deputy Director Andrew McCabe to be involved in the Russia investigation. The president complained McCabe was biased against him and cited McCabe's wife, Jill, who ran unsuccessfully as a candidate for the Virginia state Senate.

McCabe was fired from the FBI on March 16, 2018, after the Justice Department's Office of the Inspector General determined he misled investigators about the role he had in leaking information to the Wall Street Journal in October 2016 about the investigation into the Clinton Foundation.

Sources said Comey's refusal to state publicly whether Trump was under investigation (which he repeatedly told the president in private that he was not) was due to a decision made by Rosenstein and top DOJ official Dana Boente.

The draft letter, which the report states was largely dictated by Trump himself, was shown to Rosenstein and Attorney General Jeff Sessions during a meeting at the White House. Both agreed to write their own recommendations to fire Comey. It was at this meeting Rosenstein considered surreptitiously taking the draft letter out of the White House because it had the potential to be incriminating evidence, he told a longtime Justice Department official.

The New York Review of Books stated that Rosenstein "was nervous as he considered walking out of the White House with the letter in case he was detected spiriting it away" and wondered that if he went along with Trump's story on the reasons for the firing "he himself might have unwittingly acted as an accessory to a presidential obstruction of justice". Rosenstein believed the letter was "potentially incriminating evidence."

Trump fired Comey on May 9, using Rosenstein's memo, which was critical of Comey for his handling of the investigation into Hillary Clinton's email server, but not the Russia investigation. Sessions, who had recused himself from the Russia investigation, wrote an accompanying letter recommending Comey's removal.

In the days that followed, Rosenstein reportedly spiraled into rage and paranoia as he felt like he was being used by the White House, even as Trump himself acknowledged publicly that the "Russia thing" played into his decision to fire Comey.

It was during this period that Rosenstein was said to have discussed wearing a “wire” to record conversations with Trump and recruiting Cabinet members to invoke the 25th Amendment to remove the president from office. Rosenstein and his staff brushed off these reports of his comments as either untrue or that what he said was meant as a joke.

On May 17, Rosenstein appointed Mueller, a former FBI director, as special counsel. Nearly two years later, Mueller completed his Russia investigation, which also examined possible obstruction of justice by the president. Mueller's team was unable to find sufficient evidence of conspiracy between the Trump campaign and Russia and declined to make a determination about obstruction.

Mueller's report did lay out 10 instances in which Trump might have obstructed justice, but Mueller declined to make a determination on the matter, citing a Justice Department guideline that sitting presidents cannot be indicted.

Before the report's release in April, Attorney General William Barr released a summary of its principal conclusions which said he and Rosenstein decided there was not sufficient evidence to establish an obstruction crime had occurred. Still, although Trump says he has been vindicated, Democrats argue Mueller's refusal to clear Trump on obstruction provides them a road map to continue to investigate and possibly seek impeachment.

After nearly three decades of service, Rosenstein retired from the Justice Department last month on what appeared to be good terms with the president. In a speech in which he dubbed Comey a "partisan pundit," Rosenstein denied the notion that Comey's ouster was meant to influence the Russia investigation.

"Nobody said that the removal was intended to influence the course of my Russia investigation. The notion that replacing the FBI director with a new FBI director would influence the Russia investigation — or any other investigation — never crossed my mind," Rosenstein said.