Washington CNN —  

Special counsel Robert Mueller has closed his investigation into Russian meddling, and Attorney General William Barr will inform Congress about Mueller’s findings.

The big question now is exactly how much Barr is going to reveal. Anything short of a complete tell-all is sure to disappoint Democrats.

In a letter to lawmakers Friday, Barr said that he is reviewing Mueller’s report and suggested he will provide “principal conclusions as soon as this weekend.” A Justice Department official said those conclusions are expected to be made public.

Here’s what Barr must consider:

What do Justice Department rules say?

There are federal rules that dictate how a special counsel operates and how Barr should handle Mueller’s report. This is only the second case where these rules will be put to the test – the first time was 20 years ago when a special counsel investigated the deadly siege in Waco, Texas.

The regulations say Mueller should give Barr a “confidential report” explaining why he charged some people and didn’t prosecute others. Barr is then required to notify Congress that he received that report from Mueller. But there isn’t anything in the regulations that directs Barr to issue a final, comprehensive report of his own – or to release Mueller’s confidential report.

As they decide what information to provide to the public, Justice Department officials will be influenced by additional regulations and internal policies that address disclosures like this.

The Justice Manual, a collection of internal Justice Department guidelines, lays out a number of policies for situations like these.

It says that “prosecutors should remain sensitive to the privacy and reputation interests of uncharged third-parties.” The manual points to a series of court decisions establishing that there is “no legitimate government interest served” by publicizing damaging information about someone who isn’t facing charges.

But federal rules say that there could be exceptions. It all turns on whether additional public information is necessary “in the interest in the fair administration of justice and the law enforcement process.” Barr and the deputy attorney general, currently Rod Rosenstein, are the only people at the Justice Department with the power to grant these one-time exceptions.

Democratic leaders on Capitol Hill have clamored that the Russia investigation fits these special circumstances. They won’t be satisfied if Barr only sends an executive summary of sorts.

Last week, the House of Representatives voted unanimously in favor of a non-binding resolution that called for the Mueller report to be released to the public upon completion. President Donald Trump echoed the sentiment on Wednesday, telling reporters he had blessed the House Republicans’ move to join Democrats on the vote, adding, “Let it come out, let people see it.”

What has Barr said?

At his confirmation hearing on Capitol Hill earlier this year, Barr promised “transparency.”

“I also believe it is very important that the public and Congress be informed of the results of the special counsel’s work,” Barr told the Senate Judiciary Committee. “My goal will be to provide as much transparency as I can consistent with the law.”

He continued, “I can assure you that where judgments are to be made, I will make those judgments based solely on the law and I will not let personal, political or other improper interests influence my decision.”

But as the hearing went on, senators from both parties prodded Barr for details. He gave himself lots of wiggle room, making it clear he would take whatever Mueller produced and write his own report. He also said the Justice Department shouldn’t “unload negative information” on uncharged people.

The bottom line is that if Democrats want to see Mueller’s work, then Barr’s comments suggest they’ll need to put up a fight. House Democrats say they’re ready with subpoenas and lawsuits, if necessary.

What have others said about this?

Barr isn’t alone in alluding to a more tempered report than some might want. Right there with him is Rosenstein, who appointed Mueller in 2017 and oversaw most of his investigation. At a recent event, Rosenstein invoked the need for “sensitivity to the rights of uncharged people.”

“If we aren’t prepared to prove our case beyond a reasonable doubt in court, then we have no business making allegations against American citizens,” Rosenstein said at a DC think tank last month.

The deputy attorney general made the point even more explicitly two years ago in a letter recommending that Trump terminate then-FBI Director James Comey.

Rosenstein slammed Comey’s decision to give a long-winded and extremely detailed press conference after the Hillary Clinton email investigation was closed in July 2016. Rosenstein wrote that “it is a textbook example of what federal prosecutors and agents are taught not do to.”

“(Comey) ignored another longstanding principle: we do not hold press conferences to release derogatory information about the subject of a declined criminal investigation,” Rosenstein wrote.

For his part, Comey has defended the move to release the information, which included a line designating Clinton and her staff’s handling of classified information as “extremely careless.”

During those controversial remarks in 2016, Comey said his public statement was “unusual” but warranted. He said he divulged “more detail about our process than I ordinarily would, because I think the American people deserve those details in a case of intense public interest.”

In a report released last year, the Justice Department’s internal watchdog determined that Comey’s move “was inconsistent with Department policy and violated long-standing Department practice and protocol by, among other things, criticizing Clinton’s uncharged conduct.”