Former FBI director appointed 'special counsel' to oversee Russia investigation

WASHINGTON -- Deputy Attorney General Rod Rosenstein has appointed former FBI director Robert Mueller to serve as "Special Counsel to oversee the previously-confirmed FBI investigation of Russian government efforts to influence the 2016 presidential election, and related matters."

Rosenstein is acting Attorney General in the case because Attorney General Jeff Sessions recused himself.

Mueller, a former U.S. attorney in San Francisco, will once again have all of the authorities afforded to that position -- including ability to take the matter before a grand jury and ability to issue subpoenas.

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The appointment Wednesday comes amid a growing Democratic outcry for someone outside the Justice Department to handle the politically charged investigation.

It follows the revelation Tuesday that fired FBI Director James Comey wrote in a memo that Trump had asked him to end an investigation into former national security adviser Michael Flynn.

Rosenstein said in statement: "in my capacity as acting Attorney General, I determined that it is in the public interest for me to exercise my authority and appoint a Special Counsel to assume responsibility for this matter. My decision is not a finding that crimes have been committed or that any prosecution is warranted. I have made no such determination. What I have determined is that based upon the unique circumstances, the public interest requires me to place this investigation under the authority of a person who exercises a degree of independence from the normal chain of command. ... a Special Counsel is necessary in order for the American people to have full confidence in the outcome. Our nation is grounded on the rule of law, and the public must be assured that government officials administer the law fairly. Special Counsel Mueller will have all appropriate resources to conduct a thorough and complete investigation, and I am confident that he will follow the facts, apply the law and reach a just result."

Mueller is resigning from his law firm in order to avoid any conflicts of interest with firm clients or attorneys. He was appointed FBI director in 2001 and led the FBI through the aftermath of the Sept. 11 terror attacks. He retired in 2013.

ABC News and the Associated Press contributed to this report