United States Department of Justice Office of Special Counsel

The Office of Special Counsel was an office of the United States Department of Justice established by provisions in the Ethics in Government Act that expired in 1999. The provisions were replaced by Department of Justice regulation 28 CFR Part 600, which created the successor office of special counsel. The current regulations were drafted by former acting Solicitor General Neal Katyal.
The Independent Counsel was an independent prosecutor—distinct from the Attorney General of the United States Department of Justice—who provided reports to the United States Congress under .
History.
In 1978, a Democratic Party-majority Congress was determined to curb the powers of the President and other senior executive branch officials due in part to the Watergate scandal and related events such as the Saturday Night Massacre. They drafted and passed the Ethics in Government Act of 1978, creating a special prosecutor (later changed to Independent Counsel) position, which could be used by Congress or the Attorney General to investigate individuals holding or formerly holding certain high positions in the federal government and in national Presidential election campaign organizations.
The prosecutor, who was appointed by a special panel of the United States Court of Appeals for the District of Columbia Circuit, could investigate allegations of any misconduct, with an unlimited budget and no deadline, and could be dismissed only by the Attorney General for "good cause" or by the special panel of the court when the independent counsel's task was completed. As the president could not dismiss those investigating the executive branch it was felt that the independence of the office would ensure impartiality of any reports presented to Congress. However, there have been critics of this law including Supreme Court Justice Antonin Scalia. Many argued the new Independent Counsel's office was a sort of "fourth branch" of government that had virtually unlimited powers and was answerable to no one. However, the constitutionality of the new office was ultimately upheld in the 1988 Supreme Court case "Morrison v. Olson".
Previously under the Independent Counsel Reauthorization Act of 1994, United States Attorney General Janet Reno had Donald Smaltz appointed Independent Counsel by the United States Court of Appeals for the District of Columbia (Division for the Purpose of Appointing Independent Counsels Ethics in Government Act of 1978, As Amended, Division 94-2) on September 9, 1994, to "investigate to the maximum extent authorized by law" whether the US Department of Agriculture Secretary Mike Espy "committed a violation of any federal criminal law . . . relating in any way to the acceptance of gifts by him from organizations or individuals with business pending before the Department of Agriculture." Smaltz was also given jurisdiction to investigate "other allegations or evidence of violations of any federal criminal law by organizations or individuals developed during the course of the investigation of Secretary Espy and connected with or arising out of that investigation."
The most famous Independent Counsel was Kenneth Starr, whose report led to the impeachment of President Bill Clinton by the United States House of Representatives, though he was later acquitted by the United States Senate.
Three Independent Counsel investigations had jurisdictions that were specified in regulations: the Iran-Contra investigation in 1987 (28 Code of Federal Regulations sec. 601.1); Edwin Meese III, the Wedtech case in 1987 (sec. 602.1), and President Bill and First Lady Hillary Clinton in the Madison Guaranty/Whitewater case in 1994 (sec. 603.1). 
After the expiration of the Ethics in Government Act in 1999, the Office of Independent Counsel was replaced with the office of Special Counsel, defined by regulation 28 CFR 600, which in turn is based on Congressional statute 28 USC 510. 
Patrick Fitzgerald was appointed Special Counsel in 2003 regarding the investigation into the public naming of CIA spy Valerie Plame. His appointment was based on 28 USC 510.
Under 28 CFR 600, Robert Mueller was appointed Special Counsel in 2017 to investigate possible interference by the Russian government in the 2016 presidential election, including a possible criminal conspiracy between Russia and the presidential campaign of Donald Trump. The investigation concluded in 2019 with a 448-page final report and 34 indictments.