The Justice Department appointed a special counsel Wednesday to investigate possible coordination between Trump associates and Russian officials — a clear signal to the White House that federal investigators will aggressively pursue the matter despite the president’s insistence that there was no “collusion’’ with the Kremlin.
Robert S. Mueller III, a former prosecutor who served as the FBI director from 2001 to 2013, has agreed to take over the investigation as a special counsel, Deputy Attorney General Rod J. Rosenstein announced.