“The inspector general’s report now makes clear that the F.B.I. launched an intrusive investigation of a U.S. presidential campaign on the thinnest of suspicions that, in my view, were insufficient to justify the steps taken,” Mr. Barr said in a statement.
The report, as well as Mr. Barr’s criticism, is certain to extend the debate over the legitimacy of the F.B.I.’s inquiry, which grew into the special counsel investigation led by Robert S. Mueller III. Mr. Barr has publicly said he thinks the Trump campaign was subjected to “spying” and tapped John H. Durham, the United States attorney in Connecticut, to lead yet another investigation into the Russia investigation.
Though the report largely exonerated F.B.I. officials of the president’s most inflammatory accusations, Mr. Trump’s persistent attacks have nonetheless already damaged the bureau’s reputation. Top officials were fired, while others left the bureau.
Much of the report focused on the paperwork associated with the wiretapping of Mr. Page, who was first approved for targeting in October 2016, about a month after he had stepped down from the Trump campaign. The Justice Department obtained three renewals of court permission to eavesdrop on Mr. Page — two under the Trump administration.
The four applications contained dozens of significant inaccuracies, material omissions or assertions that were not backed in supporting documents, according to the report, which grouped them in a chart. The applications for the wiretap relied on historical information about Mr. Page’s contacts before 2016, and claims about his 2016 interactions with Russians came from a notorious dossier of opposition research collected by Christopher Steele, a former British intelligence agent paid by Democrats.
For example, the F.B.I. never told the main Justice Department, which in turn never told the court, that Mr. Page had for years been providing information to the C.I.A. about his prior contacts with Russian intelligence officials, including an encounter cited in the application as a reason to be suspicious of him. That made his history less suspicious, Mr. Horowitz suggested.
The F.B.I.’s omission of Mr. Page’s contacts with the C.I.A. relates to the criminal referral that Mr. Horowitz made about an F.B.I. lawyer assigned to assist the Russia investigation team. He found that the lawyer, Kevin Clinesmith, altered an email from the C.I.A. to a colleague during a renewal application.