What to Know Special counsel Robert Mueller on Friday turned over his final report on Russian election meddling

Attorney General William Barr said he will soon report to Congress on Mueller's findings

Many Democrats called for the release of the entire Mueller report

Special counsel Robert Mueller on Friday turned over his long-awaited final report on the contentious Russia investigation, ending a probe that has cast a dark shadow over Donald Trump's presidency with no new charges but launching a fresh wave of political battles over the still-confidential findings.

The 22-month probe ended without additional indictments by Mueller despite public speculation by congressional Democrats and others that members of the president's family, including his oldest son, could themselves wind up facing charges.

The Justice Department said the report was delivered by a security officer Friday afternoon to the office of Deputy Attorney General Rod Rosenstein, and then it went to Attorney General William Barr. Word of the delivery triggered reactions across Washington, including Democrats' demands that it be released to the public and Republicans' contentions that it ended two years of wasted time and money.

The next step is up to Barr, who is charged with writing his own account of Mueller's findings and sending it to Congress. In a letter to lawmakers , he declared he was committed to transparency and speed. He said he could provide the special counsel's "principal findings" to Congress this weekend, but that likely won't be the last of the information he provides to lawmakers or the public.

The attorney general said the Justice Department had not denied any request from the special counsel, something Barr would have been required to disclose to ensure there was no political inference.

The White House sought to keep some distance, saying it had not seen or been briefed on the document.

With no details released at this point, it's not known whether Mueller's report answers the core questions of his investigation: Did Trump's campaign collude with the Kremlin to sway the 2016 presidential election in favor of the celebrity businessman? Also, did Trump take steps later, including by firing his FBI director, to obstruct the probe?

But the delivery of the report does mean the investigation has concluded without any public charges of a criminal conspiracy between the campaign and Russia, or of obstruction by the president. A Justice Department official confirmed Friday that Mueller was not recommending any further indictments.

That person, who described the document as "comprehensive," was not authorized to discuss the probe and asked for anonymity.

That's good news for a handful of Trump associates and family members dogged by speculation of possible wrongdoing. They include Donald Trump Jr., who had a role in arranging a Trump Tower meeting at the height of the 2016 election campaign with a Kremlin-linked lawyer, and Trump's son-in-law, Jared Kushner, who was interviewed at least twice by Mueller's prosecutor. It wasn't immediately clear whether Mueller might have referred additional investigations to the Justice Department.

All told, Mueller charged 34 people, including the president's former campaign chairman, Paul Manafort, his first national security adviser, Michael Flynn, and three Russian companies. Twenty-five Russians were indicted on charges related to election interference, accused either of hacking Democratic email accounts during the campaign or of orchestrating a social media campaign that spread disinformation on the internet. Five Trump aides pleaded guilty and agreed to cooperate with Mueller and a sixth, longtime confidant Roger Stone, is awaiting trial on charges that he lied to Congress and engaged in witness tampering.

It's unclear what steps Mueller will take if he uncovered what he believes to be criminal wrongdoing by Trump, in light of Justice Department legal opinions that have held that sitting presidents may not be indicted.

The mere delivery of a confidential report set off swift, full-throated demands from Democrats for full release of Mueller's findings.

House Speaker Nancy Pelosi and Senate Minority Leader Chuck Schumer declared it "imperative" to make the full report public, a call echoed by several Democrats vying to challenge Trump in 2020.

"The American people have a right to the truth," Schumer and Pelosi said in a joint statement.

Democrats also expressed concern that Trump would try to get a "sneak preview" of the findings.

"The White House must not be allowed to interfere in decisions about what parts of those findings or evidence are made public," they said in a joint statement.

It was not clear whether Trump, who is spending the weekend at his resort in Mar-a-Lago, would have early access to Mueller's findings. Spokeswoman Sarah Sanders suggested the White House would not interfere, saying "we look forward to the process taking its course." But Trump's personal attorney, Rudy Giuliani, told The Associated Press the legal team would seek to get "an early look" at the findings before they were made public.

He said it would be "appropriate" for the White House to be able "to review matters of executive privilege" but he had received no assurances from the Department of Justice. He later softened his stance, saying the decision was "up to DOJ and we are confident it will be handled properly."

Barr's chief of staff called White House Counsel Emmet Flood Friday about 20 minutes before notifying lawmakers of the report's arrival. Barr's congressional letter went to the Republican and Democratic leaders of the Senate and House Judiciary committees.

The chairman of the Senate panel, Lindsey Graham of South Carolina, was keynote speaker Friday night at a Palm Beach County GOP dinner attended by Trump at Mar-a-Lago.

Barr has said he wants to make as much public as possible, and that any efforts to withhold details will prompt a tussle between the Justice Department and lawmakers who may subpoena Mueller and his investigators to testify before Congress. Rep. Adam Schiff, D-Calif., threatened a subpoena Friday.

Such a move would likely be vigorously contested by the Trump administration.

The conclusion of Mueller's investigation does not remove legal peril for the president . Trump faces a separate Justice Department investigation in New York into hush money payments during the campaign to two women who say they had sex with him years before the election. He's also been implicated in a potential campaign finance violation by his former lawyer, Michael Cohen, who says Trump asked him to arrange the transactions. Federal prosecutors, also in New York, have been investigating foreign contributions made to the president's inaugural committee.

No matter the findings in Mueller's report, the investigation has already illuminated Russia's assault on the American political system, painted the Trump campaign as eager to exploit the release of hacked Democratic emails and exposed lies by Trump aides aimed at covering up their Russia-related contacts.

The special counsel brought a sweeping indictment accusing Russian military intelligence officers of hacking Democrat Hillary Clinton's campaign and other Democratic groups during the 2016 campaign. He charged another group of Russians with carrying out a large-scale social media disinformation campaign against the American political process that also sought to help Trump and hurt Clinton.

Closer to the president, Mueller secured convictions against a campaign chairman who cheated banks and dodged his taxes, a national security adviser who lied about his Russian contacts and a campaign aide who misled the FBI about his knowledge of stolen emails.

Cohen, the president's former lawyer, pleaded guilty in New York to campaign finance violations arising from the hush money payments and in the Mueller probe to lying to Congress about a Moscow real estate deal. Another Trump confidant, Stone, is awaiting trial on charges that he lied about his pursuit of Russian-hacked emails ultimately released by WikiLeaks. It's unclear whether any of the aides who have been convicted, all of whom have pleaded guilty and cooperated with the investigators, might angle for a pardon. Trump has left open the idea of pardons.

Along the way, Trump lawyers and advisers repeatedly evolved their public defenses to deal with the onslaught of allegations from the investigation. Where once Trump and his aides had maintained there were no connections between the campaign and Russia, by the end of the probe Trump attorney Giuliani was routinely making the argument that even if the two sides did collude, it wasn't necessarily a crime. The goalpost shifting reflected the administration's challenge in adopting a singular narrative to fend off allegations.

Equally central to Mueller's work was his inquiry into whether the president tried to obstruct the investigation. Since the special counsel's appointment in May 2017, Trump has increasingly tried to undermine the probe by calling it a "witch hunt" and repeatedly proclaiming there was "NO COLLUSION" with Russia.

But one week before Mueller's appointment, Trump fired FBI Director James Comey, later saying he was thinking of "this Russia thing" at the time.

He mercilessly harangued Attorney General Jeff Sessions for recusing himself from the Russia investigation two months before Mueller was named special counsel, a move that left the president without a perceived loyalist atop the probe. And he helped draft a misleading statement on Air Force One as the Trump Tower meeting between his eldest son and a Kremlin-connected lawyer was about to become public.

Even as Trump blasted Mueller's team, his White House and campaign produced thousands of documents for the special counsel, and dozens of his aides were interviewed. The president submitted written answers to Mueller regarding the Russia investigation, but he refused to be interviewed