A total of thirty-four individuals and three companies were indicted by Mueller's investigators. Eight have pleaded guilty to or been convicted of felonies, including five Trump associates and campaign officials. None of those five convictions "involved a conspiracy between the campaign and Russians" and "Mueller did not charge or suggest charges for [...] whether the Trump campaign worked with the Russians to influence the election". The investigation was, however, more complex. On May 29, 2019, In a press conference, Mueller stated that "If we had confidence that the president clearly did not commit a crime, we would have said that. We did not, however, make a determination as to whether the president did commit a crime... A president cannot be charged with a federal crime while he is in office. That is unconstitutional. Even if the charge is kept under seal and hidden from public view – that too is prohibited."
Roger Stone, a longtime Trump advisor who had met with a Russian person offering to sell derogatory financial information about Hillary Clinton, was indicted on seven charges of lying to Congress and witness tampering. He pled not guilty. The jury subsequently found him guilty on all seven counts.
Dozens of ongoing investigations originally handled by the Special Counsel's office were forwarded to district and state prosecutors, other Department of Justice (DoJ) branches, and other federal agencies.
The investigation was officially concluded on March 22, 2019, with the Mueller Report submitted to Attorney GeneralWilliam Barr. Barr had been critical of the investigation before he became Attorney General. A redacted version of the report was released to the public on April 18, 2019. The report concluded that the IRA's social media campaign supported Trump's presidential candidacy while attacking Clinton's, and Russian intelligence hacked and released damaging material from the Clinton campaign and various Democratic Party organizations. The investigation "identified numerous links between the Russian government and the Trump campaign", and determined that the Trump campaign "expected it would benefit electorally" from Russian hacking efforts. However, ultimately "the investigation did not establish that members of the Trump campaign conspired or coordinated with the Russian government in its election interference activities". The evidence was not necessarily complete due to encrypted, deleted, or unsaved communications as well as false, incomplete, or declined testimony. Mueller later said that the investigation's conclusion on Russian interference "deserves the attention of every American".
On potential obstruction of justice by President Trump, the investigation "does not conclude that the President committed a crime", as investigators would not indict a sitting president per an Office of Legal Counsel (OLC) opinion, and would not accuse him of a crime when he cannot clear his name in court. However, the investigation "also does not exonerate" Trump, finding both public and private actions "by the President that were capable of exerting undue influence over law enforcement investigations".Ten episodes of potential obstruction by the president were described. The report states that Congress can decide whether Trump obstructed justice, and has the authority to take action against him. Attorney General Barr and Deputy Attorney General Rod Rosenstein, who had authorized the Mueller probe, decided on March 24, 2019, that the evidence was insufficient to establish a finding of obstruction of justice. Upon his resignation on May 29, 2019, Mueller stated that: "the Constitution requires a process other than the criminal justice system to formally accuse a sitting president of wrongdoing". In July 2019, Mueller testified to Congress that a president could be charged with obstruction of justice (or other crimes) after they left office.