WASHINGTON - The Justice Department has appointed Robert S. Mueller III, the former F.B.I. director, to serve as a special counsel to oversee its investigation into Russian meddling in the election, Deputy Attorney General Rod J. Rosenstein announced on Wednesday.
The appointment of Mr. Mueller dramatically raises the stakes for President Trump in the multiple investigations into his campaign's ties to the Russians. It follows a swiftly moving series of developments that have roiled Washington, including Mr. Trump's abrupt dismissal of the F.B.I. director, James B. Comey, and the disclosure that the president urged Mr. Comey to drop the bureau's investigation into his former national security adviser, Michael T. Flynn.
"I determined that it is in the public interest for me to exercise my authorities and appoint a special counsel to assume responsibility for this matter," Mr. Rosenstein said in a statement. "My decision is not a finding that crimes have been committed or that any prosecution is warranted. I have made no such determination."
While a special counsel would remain ultimately answerable to Mr. Rosenstein - and by extension, the president - he would have greater autonomy to run an investigation than a United States attorney.
Mr. Mueller is expected to announce his resignation from the law firm WilmerHale.