A federal judge has ordered the Department of Justice to release a critical legal memorandum prepared by Justice Department lawyers in 2019 that cleared then-President Donald Trump of criminal charges related to Robert Mueller's investigation into Russia collusion and Trump's presidential campaign.

What is the background?

Then-Attorney General William Barr wrote Congress on March 24, 2019, explaining that Mueller's investigation "did not find that the Trump campaign or anyone associated with it conspired or coordinated with Russia in its efforts to influence the 2016 U.S. presidential campaign." Secondly, Barr explained that Mueller did not make a determination whether Trump committed obstruction of justice, but instead left that decision to Barr, who subsequently decided that Trump would not face criminal charges.

Barr told Congress he reached his conclusion "in consultation with the Office of Legal Counsel and other Department lawyers."

Citizens for Responsibility and Ethics in Washington, a nonpartisan government watchdog, subsequently filed a Freedom of Information Act request seeking the government documents provided to Barr prior to his decision. Obtaining the documents for purposes of accountability was especially important because Mueller disputed Barr's characterization of his investigatory findings.

"The summary letter the Department sent to Congress and released to the public late in the afternoon of March 24 did not fully capture the context, nature, and substance of this Office's work and conclusions," Mueller said, in part, on March 27, 2019.

However, the DOJ refused to provide the documents, including the legal memo that Barr reviewed, arguing the memo was exempt from FOIA requests under exceptions for deliberative government decision making and attorney-client privilege.

What did the judge say?

U.S. District Court Judge Amy Berman Jackson, an Obama appointee, released a scathing 41-page opinion Monday rejecting the DOJ's arguments and ordered the critical memo to be released.

Jackson released her opinion after reviewing the memo for herself, and she said it contained "strategic, as opposed to legal advice."

In part, Jackson took issue with the fact that not prosecuting Trump "was a given" for Barr's DOJ.

"The review of the document reveals that the Attorney General was not then engaged in making a decision about whether the President should be charged with obstruction of justice; the fact that he would not be prosecuted was a given," Jackson wrote.

Jackson went on to write:

Not only was the Attorney General being disingenuous then, but DOJ hasbeen disingenuous to this Court with respect to the existence of a decision-making process thatshould be shielded by the deliberative process privilege. The agency's redactions and incompleteexplanations obfuscate the true purpose of the memorandum, and the excised portions belie thenotion that it fell to the Attorney General to make a prosecution decision or that any such decisionwas on the table at any time.

In fact, Jackson discovered Barr's letter to Congress and the legal memo from the Office of Legal Counsel were being prepared at the "same time," all the more reason the memo should not be protected from FOIA requests.

"Since the memorandum was being written at the same time and by the same people who were drafting the Attorney General's letter to Congress setting forth his views on the basis for a prosecution, and the record reflects that the priority was to get the letter completed first...one simply cannot credit the declarant's statement that the Attorney General made the 'decision' he announced based on the advice the memo contains," Jackson wrote.

Jackson gave the DOJ until May 17 to file a motion to stay the release of the memo.