WASHINGTON (CBSNewYork/CBS News) -- Former FBI Director Robert Mueller has been appointed to serve as special counsel to oversee the previously confirmed investigation of Russian efforts to influence the 2016 presidential election and related matters.
Deputy Attorney General Rod Rosenstein announced the appointment on Wednesday.
"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," Rosenstein said in a news release. "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."
Rosenstein said while the Department of Justice conducts thousands of criminal investigations without regard for partisanship each year, a special counsel is necessary for the Russia probe.
"Our nation is grounded on the rule of law, and the public must be assured that government officials administer the law fairly," Mueller said in the release. "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."
Late Wednesday, Mueller put out a short statement saying he accepts the special counsel responsibility and will "discharge it to the best of my ability."
Mueller has agreed to resign from his private law firm to avoid any conflicts of interests.
In a White House statement, President Donald Trump did not comment directly on the selection of Mueller, but said an investigation would prove there was no collusion with Russia or any country.
"As I have stated many times, a thorough investigation will confirm what we already know – there was no collusion between my campaign and any foreign entity. I look forward to this matter concluding quickly," Trump said in the statement. "In the meantime, I will never stop fighting for the people and the issues that matter most to the future of our country."
U.S. Rep. Jason Chaffetz (R-Utah) chairs the House Oversight Committee. He applauded the selection of Mueller.
"Director Mueller -- impeccable credentials," Chaffetz said. "I think will provide a great deal of comfort on both sides of the aisle. It's a real professional. People will have great trust in him."
New York lawmakers also weighed in on the appointment late Wednesday.
"It's good for the country that we get to the bottom of this," said Rep. Joe Crowley (D-N.Y.)
But Rep. Peter King (R-N.Y.) did not share the same enthusiasm.
"I don't think it was necessary. I don't, as a general rule, believe in special counsels, I think they can go off on their own," he said. "Having said that, I have a lot of confidence in Bob Mueller."
Special counsels are given broad investigatory power and conduct much of their work in secret.
Mueller was appointed FBI director in 2001 and served in the position until 2013. FBI directors are appointed to ten-year terms, but President Barack Obama added two years to his tenure.
A career prosecutor and veteran of the Marine Corps during the Vietnam War, Mueller is a widely respected figure in Washington.
The appointment comes as numerous Democratic lawmakers have called for a special counsel, colloquially known as a special prosecutor.
As CBS2's Andrea Grymes reported, this latest development also comes on the heels of revelations that fired FBI Director James Comey reportedly wrote a memo in February claiming that President Trump asked him to drop the investigation into former National Security Director Michael Flynn.
Flynn had been fired for misleading the administration about his conversations with the Russians.
But in both the House and Senate, there was a heated response from Democrats.
"Impeachment!" said Rep. Al Green (D-Texas).
"It's no small matter when we're talking about impeaching the president of the United States," said Sen. Kamala Harris (D-Calif.)
"Some people say, 'Oh my God, she said the word impeachment,'" said Rep. Maxine Waters (D-Calif.)
But Queens U.S. Rep. Joe Crowley (D-N.Y.) said such talk is premature.
"There needs to be a full investigation first," Crowley said. "We need to get to the facts. and let the facts lead where they may."
House Speaker Paul Ryan (R-Wis.) says people must avoid a rush to judgment.
"There's been a lot of reporting lately I think that requires close examination," Ryan said. "We need the facts. It is obvious that there are some people out there who want to harm the president. But we have an obligation to carry out our oversight regardless of which party is in the White House. That means before rushing to judgment, we get all the pertinent information."
Earlier Wednesday, Trump gave the commencement address at the U.S. Coast Guard Academy in New London, Connecticut, pointing to his own life when he told graduates never to give up when things are not fair.
"Look at the way I've been treated lately, especially by the media," Trump said at the commencement address. "No politician in history, and I say this with great surety, has been treated worse or more unfairly. You can't let them get you down, you can't let the critics and the naysayers get in the way of your dreams."
Three Republican-led committees have sent letters to the FBI asking for notes or memoranda that Comey prepared on his actions with presidents Trump and Barack Obama.
The House Oversight Committee is also holding a hearing next Wednesday. Its members hope Comey will testify.
for more features.