Here are some key findings in the 434-page report by the Justice Department's inspector general, Michael Horowitz.
No evidence for Trump's 'witch hunt' theory
The report debunked essential elements of the president's conspiracy theory. Trump and his allies claimed a wide-reaching conspiracy to use false opposition research funded by Democrats to justify opening an investigation that would allow them to infiltrate and spy on the Trump campaign and sabotage his presidency. Horowitz did not find evidence supporting that narrative. "We did not find documentary or testimonial evidence that political bias or improper motivation influenced the decisions" by the bureau, the report concluded.
What the FBI got wrong
There were procedural problems in the process of getting warrants. Horowitz cited multiple errors and omissions related in the applications to eavesdrop on former Trump campaign adviser Carter Page, findings that may bring a renewed focus on the process to obtain such warrants.
Trump's accusation about Obama's role is debunked
Trump has long claimed the Obama administration had been behind the investigation. The report found that President Barack Obama and top administration officials played no role in the investigation. Former FBI Director James Comey said he believes he told Obama and other White House officials about the outlines of the investigation in an August 2016 meeting, at least a month after it was opened. "Comey said he thought it was important that the president know the nature of the FBI' s efforts without providing any specifics," according to the report.
New York Times