A Justice Department review into the origins of the FBI's investigation into possible ties between the Trump campaign and Russian interference in the 2016 election found several procedural errors but overall no "political bias" by the agency. The review by Michael Horowitz, the inspector general for the Justice Department, also found the FBI was justified in launching its July 2016 investigation into the campaign, known as "Crossfire Hurricane."  

The 434-page report is based on more than 1 million documents from the Justice Department and the FBI and interviews with more than 100 witnesses. It examined the procedures for obtaining the 90-day surveillance warrant and renewals of that warrant for Carter Page, a Trump campaign aide. Horowitz probed the use of the Steele dossier as justification.

Attorney General William Barr challenged the findings in a statement issued immediately after the release of the Horowitz report. 

"The Inspector General's report now makes clear that the FBI 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," the statement reads. 

FBI Director Christopher Wray said in a statement that he accepted the report's findings and acknowledged that "certain FBI personnel" had failed to comply with the FBI's policies and standards of conduct. He wrote that the bureau "embraces the need for thoughtful, meaningful remedial action," and in response to the report, Wray said that he has "ordered more than 40 corrective steps to address the Report's recommendations."  

However, the Horowitz report is not the final word on the origins of the investigation. U.S. Attorney John Durham is leading a separate review of the FBI's investigation, and after Horowitz released his findings, Durham also questioned the conclusions. 

"Based on the evidence collected to date, and while our investigation is ongoing, last month we advised the Inspector General that we do not agree with some of the report's conclusions as to predication and how the FBI case was opened," Durham said in a statement.  

Durham noted that his investigation includes information from other entities outside the Justice Department, "both in the U.S. and outside of the U.S." Durham's probe is a criminal investigation, which gives him the authority to issue subpoenas to witnesses and documents, as well as to impanel a grand jury.

President Trump said he has been briefed on the report and told reporters that "the details of the report are far worse than anything I would have imagined," and he said he's still looking forward to the release of the Durham report: "It's got its own information, which is this information plus plus plus," he told reporters.

The inspector general will testify before the Senate Judiciary Committee to discuss the report on Wednesday.  

Here are some highlights from the report:

No finding of political bias in FBI decision to conduct investigation

The report does not find the FBI showed political bias in the investigation:

"We did not find any documentary or testimonial evidence that political bias or improper motivation influenced the FBI's decision to conduct these operations… no evidence that the FBI attempted to place any CHSs within the Trump Campaign…" 

FISA warrant and renewals had "significant inaccuracies and omissions"

Horowitz's team of investigators found "significant inaccuracies and omissions in each of the four applications — seven in the first FISA applications and a total of 17 by the final renewal." As a result of these 17 inaccuracies and omissions, Horowitz wrote that relevant information was not shared with and considered by decisionmakers at the Justice Department and the national security court.

All of the applications also left out information the FBI obtained from another government agency about its previous relationship with Page. 

Horowitz concluded that members of the FBI's team investigating ties between Russia and the Trump campaign "failed to meet the basic obligation" that the Carter Page FISA applications were "scrupulously accurate."

Additionally, the internal watchdog found "the surveillance of Carter Page continued even as the FBI gathered information that weakened the assessment of probable cause and made the FISA applications less accurate."

Horowitz's team wrote that while they "did not find documentary or testimonial evidence of intentional misconduct," they also "did not receive satisfactory explanations for the errors or missing information." 

The Steele Dossier

According to the report, the FBI team first proposed seeking a FISA warrant for Page in mid-August 2016, but FBI attorneys considered it "close call." In September 2016, the FBI received reporting from former British spy Christopher Steele in a document that came to be known as the Steele Dossier. 

"FBI and department officials told us the Steele reporting 'pushed [the FISA proposal] over the line' in terms of establishing probable cause. FBI leadership supported relying on Steele's reporting to seek a FISA order…"

Steele was hired around June 2016 by Fusion GPS, a Washington-based investigative firm, to determine whether then-candidate Trump had any personal or business ties to Russia, as well as whether there were ties between the Russian government and the Trump campaign.

Steele said he initially did not know that Fusion GPS had been retained by a law firm representing the Democratic National Committee (DNC), but became aware of the DNC's role by late July 2016.

Steele rejected claims that his research was "opposition research" and biased against Mr. Trump, and instead told the inspector general's team that such an allegation regarding his feelings toward the candidate was "ridiculous."

Instead, Steele said he likely was "favorably disposed" toward the Trump family before beginning his research because he had "been friendly" with a member of the Trump family for several years and visited that family member at Trump Tower.

Steele even gave the Trump family member a "family tartan from Scotland," according to Horowitz's report.

Trump supporters among FBI personnel

While a June 2018 inspector general report uncovered derogatory messages about Mr. Trump exchanged by FBI employees, in this investigation, Horowitz found text messages exchanged by FBI officials that reflect support for then-candidate Trump.

The day after the election, November 9, a supervisory special agent with the bureau reached out to another FBI employee about recent reporting from a confidential human source about the Clinton Foundation. The agent wrote "if you hear talk of a special prosecutor … I will volunteer to work [on] the Clinton Foundation."

The supervisory special agent also wrote in instant messages that day he "was so elated with the election" and equated it to "watching a Superbowl comeback." He then told the inspector general's office he "fully expected Hillary Clinton to walk away with the election. But as the returns [came] in … it was just energizing to me to see … [because] I didn't want a criminal to be in the White House."

Other FBI employees also exchanged instant messages that were supportive of Trump after the election.

"Trump!" a handling agent wrote in an instant message to the co-case handling agent for a confidential human source."

"Hahaha. Sh*t just got real," the co-case handling agent replied.

In another message, the co-case handling agent wrote, "I saw a lot of scared MFers on … [my way to work] this morning. Start looking for new jobs fellas. Haha."

After the handling agent replied, "LOL," the co-case handling agent wrote, "Come January I'm going to just get a big bowl of popcorn and sit back and watch."

FBI had informants with ties to candidate Trump

The inspector general's office learned through the course of its probe that in 2016, the FBI had "several" confidential sources with "either a connection to candidate Trump or a role in the Trump campaign."

Some of these informants were known to the FBI team investigating ties between Russia's interference in the 2016 election and the Trump campaign, and others were not.

For example, one confidential source, who was not involved in the campaign but knew Trump and had been in contact with him, had general information about Page and former Trump campaign chairman Paul Manafort, which the FBI team received in August 2016.

The information the source provided about Page was "open-source information" that was available online, and once the FBI received the information, the "matter was dropped," the source's handling agent told the Justice Department watchdog.

The inspector general's office also found an October 2016 email written to a supervisory special agent by an intelligence analyst on the Crossfire Hurricane team that included information from a different informant's file stating he or she was "scheduled to attend a 'private' national security forum" with Trump that month, after which the source would provide "an update on the Trump meeting."

But the informant's handling agent told the Justice Department watchdog that the gathering was similar to a campaign speech or discussion, rather than a meeting.

The agent said he couldn't recall if the source attended and said he "would certainly not be tasking a source to go attend some private meeting with a candidate, any candidate, for president or for other office, to collect the information on what that candidate is saying."

The inspector general said it did not find evidence that the informant "ever reported any information collected from a meeting with Trump or a Trump campaign event."

"Although the Crossfire Hurricane team was aware of these [confidential human sources] during the 2016 presidential campaign, we were told that operational use of these [sources] would not have furthered the investigation, and so these [sources] were not tasked with any investigative activities," the inspector general wrote in his report.

Recommendations for further action

As part of the inspector general's recommendations to the FBI and the Justice Department, Horowitz urged the bureau to "review the performance of all employees who had responsibility for the preparation, Woods review, or approval of the FISA application ... managers, supervisors, and senior officials in the chain of command of the Carter Page investigation."

Read the full report here.

Before he took office as attorney general, Barr said he had "a lot of questions" about intelligence activities involving the Trump campaign in the summer of 2016. He told CBS News' Jan Crawford in May that "some of the facts don't hang together with the official explanations of what happened." At the time, he thought "there was probably a failure among a group of leaders there at the upper echelon."

But Barr expressed concern that Horowitz's probe might not be sufficiently comprehensive because he had "limited powers," he told Crawford. Horowitz would not be able to compel testimony and didn't have the power "to investigate beyond the current cast of characters at the Department of Justice." He explained that Horowitz's ability to obtain information from former officials or agencies outside the Justice Department was "very limited."

President Trump and his allies believe that the FBI relied on insufficient evidence to request a FISA (Foreign Intelligence Surveillance Act) warrant to surveil Page. The FBI's investigation was handed off to special counsel Robert Mueller in May 2017. Mueller concluded his 22-month probe earlier this year.

Mr. Trump has repeatedly referred to the investigation into his campaign as a "witch hunt." But the Mueller report found that there were links between Russian individuals and campaign officials, and confirmed that Russia interfered in the 2016 election with the goal of aiding Mr. Trump's campaign.