One week after President Donald Trump fired the head of the FBI and raised fears about the future of the agency’s investigation into ties between the Trump campaign and Russia, the Department of Justice has appointed a widely admired former FBI director to lead an independent inquiry.

The newly named special counsel, Robert Mueller, was James Comey’s predecessor as FBI director. He and Comey drew widespread attention, and admiration, in an infamous showdown during the George W. Bush administration.

In March 2004, Attorney General John Ashcroft was in intensive care when White House Counsel Alberto Gonzales and Chief of Staff Andrew Card rushed to the hospital to persuade Ashcroft to renew Bush’s domestic wiretapping operation, which the Department of Justice had just declared illegal. Comey, then deputy attorney general, learned of the ploy, and he and FBI Director Mueller raced to arrive at Ashcroft’s room first. Comey stood by as Ashcroft roused himself and refused to sign the reauthorization.

Mueller was the longest-serving head of the bureau since J. Edgar Hoover, holding the position for 12 years. The 2001 George W. Bush appointee was set to step down in 2011 but was asked to stay on by President Barack Obama, despite the position’s 10-year term. Obama asked Congress to allow the extension to lend some continuity as new leaders came aboard at the Pentagon and the CIA.

After he left the FBI, Mueller was hired by the NFL to investigate the league’s response to a surveillance video that captured Baltimore Ravens running back Ray Rice punching his fiancee in an elevator in 2014. Mueller’s report, which found that the NFL had not seen the video before TMZ released it, supported the league’s explanation, but his conclusion was met with some criticism.

Most recently, Mueller has been a partner at WilmerHale, the law firm where Jamie Gorelick, who represents Trump’s daughter Ivanka and son-in-law Jared Kushner, is a partner. The Justice Department said Mueller is resigning from the law firm to become special counsel.

His appointment by Deputy Attorney General Rod Rosenstein to lead the investigation into Russian influence on the 2016 presidential election was met with support from those of various political stripes.

Brian Fallon, press secretary for Hillary Clinton’s presidential campaign, said the WilmerHale connection to Ivanka Trump and her husband does not “shake” his confidence in Mueller.

This is fair to point out, but does not shake confidence in Mueller. Country can trust in his independence.https://t.co/nhAnszOCni — Brian Fallon (@brianefallon) May 17, 2017

Rep. Jason Chaffetz (R-Utah), chairman of the House Committee on Oversight and Government Reform, cheered the selection of Mueller on Twitter.

Mueller is a great selection. Impeccable credentials. Should be widely accepted. — Jason Chaffetz (@jasoninthehouse) May 17, 2017

Rep. Adam Kinzinger (R-Ill.) told reporters that the appointment was “the right move.”

GOP Rep. Adam Kinzinger applauds appointment of Mueller: "This is the right move." (via @MSNBC) pic.twitter.com/XBZC95kDdM — Kyle Griffin (@kylegriffin1) May 17, 2017

The U.S. attorney in Manhattan who was fired by Trump in March, Preet Bharara, said Mueller is “independent and no-nonsense.”

Having known him for years, I believe special counsel Mueller is a very good thing. He is one of the best -- independent and no-nonsense. https://t.co/nMQo6aHalM — Preet Bharara (@PreetBharara) May 17, 2017

Eric Holder, who was an attorney general in the Obama administration, called Mueller a “great choice” and a man who is “incorruptible.”

As special counsel, Mueller will have all the authority of a U.S. attorney to conduct his investigation. He has significant autonomy, able to choose members of his team and the degree to which to consult the Justice Department on his progress. He answers only to the deputy attorney general.

Attorney General Jeff Sessions recused himself from involvement in the Russia investigation because of his own contact with the Russian ambassador to the U.S. during the Trump campaign.

Democrats have been urging the appointment of a special counsel since Trump fired Comey last week. Those calls grew louder as a number of bombshell news reports emerged raising questions about Trump’s dealings with Russia and Comey.

The Washington Post reported Monday that Trump had disclosed classified “code-word” information during an Oval Office meeting with Russian Foreign Minister Sergei Lavrov and Ambassador Sergey Kislyak.

The New York Times published a report Tuesday saying that Trump had asked Comey to end the FBI investigation into former national security adviser Michael Flynn, who was fired over his communications with Russian officials.