Investigations
After he assumed office, Trump was the subject of increasing Justice Department and congressional scrutiny, with investigations covering his election campaign, transition, and inauguration, actions taken during his presidency, his private businesses, personal taxes, and charitable foundation. There were ten federal criminal investigations, eight state and local investigations, and twelve congressional investigations.
Financial
In April 2019, the House Oversight Committee issued subpoenas seeking financial details from Trump’s banks, Deutsche Bank and Capital One, and his accounting firm, Mazars USA. He sued the banks, Mazars, and committee chair Elijah Cummings to prevent the disclosures.
In May, DC District Court judge Amit Mehta ruled that Mazars must comply with the subpoena, and judge Edgardo Ramos of the Southern District Court of New York ruled that the banks must also comply. Trump’s attorneys appealed. In September 2022, the committee and Trump agreed to a settlement about Mazars, and the accounting firm began turning over documents.
Russian Election Interference
In January 2017, American intelligence agencies—the CIA, the FBI, and the NSA, represented by the Director of National Intelligence—jointly stated with “high confidence” that the Russian government interfered in the 2016 presidential election to favor the election of Trump.
In March 2017, FBI Director James Comey told Congress, “[T]he FBI, as part of our counterintelligence mission, is investigating the Russian government’s efforts to interfere in the 2016 presidential election. That includes investigating the nature of any links between individuals associated with the Trump campaign and the Russian government, and whether there was any coordination between the campaign and Russia’s efforts.”
Many suspicious links between Trump associates and Russian officials and spies were discovered and the relationships between Russians and “team Trump”, including Manafort, Flynn, and Stone, were widely reported by the press. Members of Trump’s campaign and his White House staff, particularly Flynn, were in contact with Russian officials both before and after the election.
On December 29, 2016, Flynn talked with Russian Ambassador Sergey Kislyak about sanctions that were imposed that same day; Flynn later resigned in the midst of controversy over whether he misled Pence. Trump told Kislyak and Sergei Lavrov in May 2017 he was unconcerned about Russian interference in U.S. elections.
Trump and his allies promoted a conspiracy theory that Ukraine, rather than Russia, interfered in the 2016 election—which was also promoted by Russia to frame Ukraine.
FBI Crossfire Hurricane and 2017 counterintelligence investigations
In July 2016, the FBI launched an investigation, codenamed Crossfire Hurricane, into possible links between Russia and the Trump campaign. After Trump fired FBI director James Comey in May 2017, the FBI opened a counterintelligence investigation into Trump’s personal and business dealings with Russia.
Crossfire Hurricane was transferred to the Mueller investigation, but Deputy Attorney General Rod Rosenstein ended the investigation into Trump’s direct ties to Russia while giving the bureau the false impression that the Robert Mueller’s special counsel investigation would pursue the matter.
Mueller investigation
In May 2017, Rosenstein appointed former FBI director Mueller special counsel for the Department of Justice (DOJ), ordering him to “examine ‘any links and/or coordination between the Russian government’ and the Trump campaign”. He privately told Mueller to restrict the investigation to criminal matters “in connection with Russia’s 2016 election interference”.
The special counsel also investigated whether Trump’s dismissal of James Comey as FBI director constituted obstruction of justice and the Trump campaign’s possible ties to Saudi Arabia, the United Arab Emirates, Turkey, Qatar, Israel, and China. Trump sought to fire Mueller and shut down the investigation multiple times, but backed down after his staff objected or after changing his mind.
In March 2019, Mueller gave his final report to Attorney General William Barr, which Barr purported to summarize in a letter to Congress. A federal court, and Mueller himself, said Barr mischaracterized the investigation’s conclusions and, in so doing, confused the public. Trump repeatedly claimed that the investigation exonerated him; the Mueller report expressly stated that it did not.
A redacted version of the report, publicly released in April 2019, found that Russia interfered in 2016 to favor Trump. Despite “numerous links between the Russian government and the Trump campaign”, the report found that the prevailing evidence “did not establish” that Trump campaign members conspired or coordinated with Russian interference. The report revealed sweeping Russian interference and detailed how Trump and his campaign welcomed and encouraged it, believing it would benefit them electorally.
The report also detailed multiple acts of potential obstruction of justice by Trump, but “did not draw ultimate conclusions about the President’s conduct”. Investigators decided they could not “apply an approach that could potentially result in a judgment that the President committed crimes” as an Office of Legal Counsel opinion stated that a sitting president could not be indicted, and investigators would not accuse him of a crime when he cannot clear his name in court.
The report concluded that Congress, having the authority to take action against a president for wrongdoing, “may apply the obstruction laws”. The House of Representatives subsequently launched an impeachment inquiry following the Trump–Ukraine scandal, but did not pursue an article of impeachment related to the Mueller investigation.
Several Trump associates pleaded guilty or were convicted in connection with Mueller’s investigation and related cases, including Manafort and Flynn. Trump’s former attorney Michael Cohen pleaded guilty to lying to Congress about Trump’s 2016 attempts to reach a deal with Russia to build a Trump Tower in Moscow. Cohen said he had made the false statements on behalf of Trump. In February 2020, Stone was sentenced to 40 months in prison for lying to Congress and witness tampering. The sentencing judge said Stone “was prosecuted for covering up for the president”.