WASHINGTON — 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.