In letter, Mueller complained Barr didn't fully capture the 'context, nature, and substance' of his report

Special Counsel Robert Mueller sent Attorney General William Barr a letter on March 27, telling him that the four-page memo Barr sent to Congress about Mueller's report on Russian meddling in the 2016 presidential election and potential obstruction of justice "did not fully capture the context, nature, and substance" of his work, The Washington Post reports.

The letter, which was reviewed by the Post, was sent after Barr said Mueller did not reach a conclusion on whether Trump attempted to obstruct justice, but Barr looked at the evidence and determined that there wasn't enough to support this charge. The report included 10 episodes of possible obstruction of justice, but Mueller said that due to Justice Department policy that says a president cannot be indicted while in office, his team could not conclude whether Trump had committed a crime.

Mueller's letter described his dissatisfaction with the discussion surrounding his report, and shocked Department of Justice officials, people with knowledge of the matter told the Post. "There is now public confusion about critical aspects of the results of our investigation," Mueller wrote. "This threatens to undermine a central purpose for which the department appointed the special counsel: to assure full public confidence in the outcome of the investigations."

Mueller requested that Barr make public the report's introductions and executive summaries, and he suggested some redactions, Justice Department officials told the Post. "Release at this time would alleviate the misunderstandings that have arisen and would answer congressional and public questions about the nature and outcome of our investigation," Mueller wrote. Officials said that a day after the letter was sent, Mueller and Barr spoke on the phone for 15 minutes, and Mueller shared his concerns over news coverage of Barr's memo.

Barr is set to appear before the Senate Judiciary Committee on Wednesday morning. Read more about Mueller's letter, and how the Department of Justice is trying to frame his response, at The Washington Post.