(CNN) -- Robert Mueller's investigation into possible obstruction of justice could not clear President Donald Trump, saying that it was unable to determine "that no criminal conduct occurred," according to a redacted version of the special counsel's report released Thursday.
Mueller's investigation into possible collusion found that members of the Trump campaign knew they would benefit from Russia's illegal actions to influence the election, but didn't take criminal steps to help, it report said.
Mueller also makes clear Congress can continue to investigate Trump.
"With respect to whether the President can be found to have obstructed justice by exercising his powers under Article II of the Constitution, we concluded that Congress has the authority to prohibit a President's corrupt use of his authority in order to protect the integrity of the administration of justice," the report said.
In the report, Mueller provided a legal justification for why the special counsel was able to investigate obstruction of justice, even if it could not indict a sitting president. The lengthy section, citing legal precedents, also alludes to Congress' power under checks-and-balances to investigate and potentially impeach the President over obstruction of justice.
"The conclusion that Congress may apply the obstruction laws to the President's corrupt exercise of the powers of office accords with our constitutional system of checks and balances and the principle that no person is above the law," the report states.
The investigation has clouded Trump's presidency for nearly two years, and Trump was clearly worried about the potential findings of Mueller, the former FBI director.
In May 2017, after Trump learned of Mueller's appointment, Trump "slumped back in his chair and said, 'Oh my God. This is terrible. This is the end of my Presidency. I'm f***ed.'"
Question of collusion
On the collusion investigation, Mueller specifically stated Trump's presidential campaign "showed interest" in WikiLeaks' releases of emails that the Russians stole from the Democrats to hurt his 2016 opponent Hillary Clinton.
"Although the investigation established that the Russian government perceived it would benefit from a Trump presidency and worked to secure that outcome, and that the campaign expected it would benefit electorally from information stolen and released through Russian efforts, the investigation did not establish that members of the Trump campaign conspired or coordinated with the Russian government in the election interference activities," the report said.
Attorney General William Barr released the report Thursday after holding a press conference where he defended his conclusion there wasn't sufficient evidence to prosecute an obstruction case.
"After nearly two years of investigation, thousands of subpoenas, and hundreds of warrants and witness interviews, the special counsel confirmed that the Russian government sponsored efforts to illegally interfere with the 2016 presidential election, but did not find that the Trump campaign or other Americans colluded in those schemes," Barr said.
Episodes of potential obstruction by Trump
In his evaluation of whether Trump obstructed justice, Mueller looked at a number of issues and areas involving the President and his aides focused on whether they were attempting to curtail the investigation.
Those areas include: the Trump campaign's response to reports about Russian support for Trump and conduct involving FBI Director James Comey and former national security adviser Michael Flynn.
Mueller's report says that after the election, "the President expressed concerns to advisers that reports of Russia's election interference might lead the public to question the legitimacy of his election."
Other areas that Mueller probed: the President's reaction to the continuing Russia investigation; the firing of Comey; the appointment of the special counsel and efforts to remove him; efforts to curtail the special counsel; efforts to prevent public disclosure of evidence; further efforts to have then-Attorney General Jeff Sessions take control of the investigation; efforts to have then-White House counsel Don McGahn deny that the President ordered him to have Mueller removed; conduct towards Flynn and former campaign chairman Paul Manafort; and conduct toward former Trump personal lawyer Michael Cohen.
Mueller did not make a "traditional prosecutorial judgment" on the obstruction question, Barr said. Instead, Barr said he concluded the evidence was "not sufficient to establish that the President committed an obstruction-of-justice offense."
"The President took no act that in fact deprived the special counsel of the documents and witnesses necessary to complete his investigation," Barr said.
Barr said the President's lawyers were permitted to read the redacted version of the report, but the President would not assert executive privilege.
Trump declares victory
At the White House, Trump said Thursday that he's having a "good day."
"They're having a good day. I'm having a good day, too. It was called no collusion. No obstruction," Trump said to cheers at a Wounded Warriors event at the White House.
"There never was by the way and there never will be. And we do have to get to the bottom of these things I will say. This should've never happened ... I say this in front of my friends, this should never happen to another president again. This hoax -- it should never happen again. Thank you."
The President did not answer questions from reporters after the event.
Mueller declined to subpoena the President because it would "delay" the investigation.
The special counsel believed it had the authority to subpoena Trump, but decided against doing so because it would delay the investigation, according to the report. The prosecutors also believed they already had a substantial amount of evidence.
"We made the decision in view of the substantial delay that such an investigative step would likely produce at a late stage in our investigation," the special counsel wrote in the report. "We had sufficient evidence to understand relevant events and to make certain assessments without the President's testimony."
The report also says that while the OLC opinion concludes that a sitting president may not be prosecuted, "it recognizes that a criminal investigation during a President's term is permissible."
The OLC opinion "also recognizes that a President does not have immunity after he leaves office," the report says.
No prosecution of Trump Jr., Sessions
Mueller's team declined to prosecute Donald Trump, Jr., and members of the campaign for campaign finance violations for their participation in the June 2016 meeting at Trump Tower, in part, because they couldn't prove that they "willfully" violated the law.
"Taking into account the high burden to establish a culpable mental state in a campaign-finance prosecution and the difficulty in establishing the required valuation, the Office decided not to pursue criminal campaign-finance charges against Trump Jr. or other campaign officials for the events culminating in the June 9 meeting," the report states.
They also didn't go after then-Sen. Jeff Sessions for making false statements or committing perjury to Congress during his confirmation hearing for attorney general in part because of the inexact wording of the questions.
Sessions testified that he did not have communications with Russians during the campaign. It was later revealed Sessions interacted with Russian Ambassador Sergey Kislyak at the Republican National Convention in Cleveland and a campaign event at the Mayflower Hotel in Washington.
Previously unknown effort by Trump to get Sessions to curtail investigation
Mueller described a previously unknown example of the President's attempts to curtail the investigation involving Trump's former campaign manager Corey Lewandowski.
Mueller says that on June 19, 2017, Trump met in the Oval Office with Lewandowski and dictated a message intended for then-Attorney General Jeff Sessions, who at that point had recused himself from matters involving the probe.
In the message, Sessions was told to publicly announce the investigation was "'very unfair' to the President, the President had done nothing wrong, and Sessions planned to meet with the special counsel and 'let [him] move forward with investigation election meddling for future elections.'" Lewandowski told Trump he understood his instructions.
A month later, Trump checked back in with Lewandowski on the status of his message. Lewandowski said the message would be delivered soon.
Ultimately, Lewandowski declined to deliver the message personally, instead asking a senior White House official -- deputy chief of staff Rick Dearborn -- to do it instead. Mueller's report says Dearborn was "uncomfortable with the task and did not follow through."
Fight over full report
Democrats have demanded to see Mueller's full, unredacted report, charging that Barr cannot be trusted to provide an accurate accounting of Mueller's findings as a Trump political appointee who previously argued against the merits of an obstruction case against the President.
Congressional Democrats rose up in anger at Barr's decision to hold a press conference before the release of the report. Five House Democratic committee chairs said in a joint statement Wednesday night that Barr should cancel the press conference and slammed Barr.
"With the Special Counsel's fact-gathering work concluded, it is now Congress' responsibility to assess the findings and evidence and proceed accordingly," the joint statement read.
House Speaker Nancy Pelosi and Senate Minority Leader Chuck Schumer jointly called for Mueller to testify before Congress publicly, saying there was a "crisis of confidence" in Barr's independence and impartiality.
"We believe the only way to begin restoring public trust in the handling of the special counsel's investigation is for special counsel Mueller himself to provide public testimony in the House and Senate as soon as possible," they said.
Democrats have been particularly suspicious at the fact that Barr and Deputy Attorney General Rod Rosenstein made the decision there was not sufficient evidence to prosecute such a case, especially in light of reports that some on Mueller's team have told others they were unsatisfied with Barr's characterization of the investigation.
In a series of tweets on Wednesday, House Judiciary Committee Chairman Jerry Nadler questioned why Barr was having a press conference to explain the report at all, saying he was "deeply troubled by reports" the White House had been briefed on the report ahead of release, as The New York Times reported. He likewise said it was "wrong" for the Justice Department to time the release of the redacted report to Congress for after Barr's press conference.
Congress will get to see a little bit more of Mueller's report and his findings than the general public once the report is delivered to them.
Federal prosecutors said in a court filing related to the case against Trump associate Roger Stone on Wednesday that there would be two versions of the redacted special counsel report, with one for public release and another, less redacted, version for a limited number of members of Congress.
Congressional Democrats have already authorized a subpoena for the full report and the underlying evidence, and they urged Barr to change course and provide them an unredacted version. They're likely to move forward now with the subpoena, which could spark a court battle between House Democrats and the Trump administration.
Barr said Thursday he would redact four types of information before making the report public: grand jury material, classified material, material about ongoing investigations and "information that would unduly infringe on the personal privacy and reputational interests of peripheral third parties."
This story is breaking and will be updated.
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