WASHINGTON – President Obama on Friday formally nominated Republican James Comey to be the next FBI director, saying the former senior Justice Department official has “law enforcement in his blood” and touting his independence and integrity.

Comey will replace Robert Mueller, who is retiring after a dozen years and led the FBI through the terrorist attacks of Sept. 11, 2001, and the tumultuous national security matters that followed.

In a ceremony in the White House’s Rose Garden, Obama credited Mueller with protecting the lives of countless Americans and called him one of the most admired public servants of our time.

“Like the Marine that he’s always been, Bob never took his eyes off his mission,” Obama said. “It’s a tribute to Bob’s trademark humility that most Americans probably wouldn’t recognize him on the street, but all of us are better because of his service.”

Comey, 52, worked with Mueller at the Justice Department during the George W. Bush administration. His nomination prompted a stream of laudatory statements Friday, including from Attorney General Eric Holder and Sen. Dianne Feinstein, D-Calif.

Comey served as acting attorney general and was at the center of bruising debates over counterterrorism policies.

He was regarded as a fierce defender of the law and nearly resigned in 2004 over concerns he raised about electronic surveillance orders he believed to be illegal.

But Comey has also come under fire from civil-liberties advocates for his role in signing off on some Bush-era “enhanced interrogation” techniques, such as waterboarding, which are considered torture under international norms. Comey called some of the techniques “wrong” and “simply awful” but approved their legality.

“Mr. Comey should use his confirmation hearing to publicly condemn all forms of torture and cruel treatment as illegal and immoral and to renounce those past decisions that permitted their use,” the St. Paul, Minn.-based Center for Victims of Torture said in a statement Friday. “He should also commit himself as FBI director to uphold legal and humane interrogation tactics in all FBI counterterrorism and counterintelligence activities.”

If confirmed by the Senate, Comey would take over the FBI as the administration faces questions about authorizing secret surveillance programs of U.S. citizens and foreigners.