Evan Perez
CNN Justice Correspondent

WASHINGTON — (CNN) FBI Director James Comey in recent weeks decided that when the bureau’s investigation into Hillary Clinton was completed, he alone would make a public announcement on the findings of investigators, but the surprising orchestration was propelled in part by the political chaos over the last week.

The result — clearing Clinton while simultaneously upbraiding her for her conduct — could help cement a legacy that shows skill in navigating some of the nation’s biggest political controversies.

Comey well understood, according to officials, his decision either way would influence the election.

On Tuesday, Comey held a press conference with little advance notice, on the same day President Barack Obama was to campaign with Clinton in North Carolina. Comey noted that he had not told his boss, Attorney General Loretta Lynch, or any other agency in the government about his decision to not recommend charges be brought against anyone in the Clinton investigation.

“They do not know what I am about to say,” Comey said, with about a dozen FBI agents and high-level officials who helped oversee the probe standing in the back of the room.

Indeed, very few knew, with most inside the FBI seemingly unaware of what he was about to say. The notice to the press only saying Comey would “speak to reporters” with no topic disclosed.

Senior law enforcement officials described the deliberations inside the FBI and Justice Department in recent months for this account. The FBI said Comey’s remarks were the only ones that would be made public. The Justice Department didn’t comment.

Comey’s solo appearance Tuesday stood out for historical reasons, because it’s highly unusual for the FBI to make public findings when investigators have decided no charges should be brought.

And Comey occasionally has publicly described his discomfort with the power wielded by the FBI’s first director, J. Edgar Hoover, particularly the surveillance of suspected enemies of the era. But his public announcement on Clinton underscored how, arguably, Comey has become the most powerful FBI director since Hoover.

It’s the power that Comey wielded Tuesday that prompted some former Justice officials to publicly criticize the FBI director.

Matthew Miller, the former top Justice spokesman under Attorney General Eric Holder, called Comey’s announcement “outrageous.”

“The FBI’s job is to investigate cases and when it’s appropriate to work with the Justice Department to bring charges,” he said on CNN.

Instead, Miller said: “Jim Comey is the final arbiter in determining the appropriateness of Hillary Clinton’s conduct. That’s not his job.”

Comey last navigated politics this turbulent in 2004, when he was deputy attorney general and he was at the center of a dramatic showdown with the White House over a surveillance program ordered by President George W. Bush. Comey and other Justice Department and FBI officials threatened to resign in the dispute, and Comey, a Republican, emerged a hero to the political left.

He is no stranger to Clinton political controversy either, having served as deputy special counsel on the Senate Whitewater Committee and also having investigated the pardon by President Bill Clinton of donor Marc Rich.

The Clinton probe posed similar thorny issues. Comey closely managed the probe, getting updates daily. With the Democratic convention just weeks away, the fate of Clinton as presumptive nominee was in the hands of the FBI.

Earlier this year, top officials at the Justice Department and FBI began formulating a rough plan for how the findings in the unusual Clinton probe would be announced, officials close to the matter said.

The idea that some top officials supported was that the FBI and the Justice Department, which have jointly managed the probe, would announce their decision together and at the same time announce how they came to it. This would prevent the spectacle of the FBI concluding its investigation then handing over recommendations to the Justice Department for review, with a final decision to be announced by Lynch.

But as the investigation drew to a close in the late spring, Comey began having other thoughts.

The political furor of the investigation was reaching a fever pitch.

FBI officials and Clinton’s lawyers began discussing plans for her interview and possible dates when she could come by FBI headquarters, preferably without a mob of reporters following her. There were some internal disputes about timing, with some at the FBI believing the interview could have happened weeks ago and Justice lawyers pushing to wait for more investigative work to be completed.

And last week, just when the political atmosphere surrounding the FBI investigation couldn’t seem more charged, things took a new bizarre turn. Former President Bill Clinton charged uninvited onto Lynch’s plane parked on the tarmac at the Phoenix airport. Lynch and the former president said they discussed nothing related to the probe and kept the visit to social matters.

Officials said Comey was already of the view that he had to make the FBI’s announcement alone. The Clinton-Lynch debacle didn’t sway him, but underscored why it was important for him to stand alone, the officials said.

Across the street at the Justice Department, Lynch already was looking for her own ways to make sure the public knew that political considerations would play no role in her final decision. Even before the untimely visit by the former president, she and her staff were weighing how to publicly describe the internal process at play, and that career prosecutors and investigators would be the ones steering any final decision.

On Friday, amid controversy over her meeting with the former president, Lynch said she would accept the decision of career officials in the department and at FBI. It was a clumsy announcement and Justice officials took pains later to make clear that Lynch wasn’t recused and Comey wasn’t now in charge.

A day later, Clinton left her home in Washington and drove a few miles to FBI headquarters for her long-awaited interview.

Officials said it was already clear that there wasn’t enough evidence to bring criminal charges. The interview cemented that decision among FBI and Justice officials who were present.

By Monday night, Comey and other FBI officials decided the public announcement should come at the earliest opportunity.

The fact that Tuesday would also mark the first public campaign appearance by Obama alongside Hillary Clinton didn’t enter in the calculation, officials said.

Comey notified the attorney general that he planned to make a public announcement but didn’t provide any details, officials said. A little after 11 a.m., as Hillary Clinton was about to take the stage at event nearby in Washington, he entered the FBI conference room and began what he called, simply, “an update on the FBI’s investigation.”

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