WASHINGTON ? Attorney General Michael B. Mukasey appointed a special prosecutor on Monday to investigate whether criminal charges should be brought against former Attorney General Alberto R. Gonzales and other officials in connection with the firings of nine of United States attorneys in 2006.

The move came as the Justice Department released a report by its inspector general severely criticizing the process that led to the firings.

The inspector general has been trying since last year to determine who in the Bush administration ordered the firings, whether the dismissals were intended to thwart investigations, and whether anyone had broken the law in carrying out the firings or in testifying about them. Critics have said the firings were politically motivated.

The 392-page report released on Monday was blistering in its assessment .

?The report makes plain that, at a minimum, the process by which nine U.S. attorneys were removed in 2006 was haphazard, arbitrary and unprofessional, and the way in which the Justice Department handled those removals and the resulting public controversy was profoundly lacking,? Mr. Mukasey said in a statement. The report called for further investigation to determine whether prosecutable offenses were committed either in the firings or in subsequent testimony about them.

Nora Dannehy, acting United States Attorney in Connecticut, will lead the investigation, Mr. Mukasey said. A graduate of Harvard Law School, she has served as a prosecutor for 17 years and specializes in white-collar and public corruption cases. She led the prosecution of the former governor of Connecticut, John Rowland, who pleaded guilty in 2004 to accepting $107,000 in gifts.Mr. Gonzales, who resigned last year after coming under criticism because of the firings, has been the main focus of interest, in part because several members of Congress charged that he may have perjured himself in his testimony through his memory lapses and misstatements about the firings.

The report found that primary blame for the ?serious failures? in the firing process lay with Attorney General Gonzalez and his deputy, Paul McNulty, ?who abdicated their responsibility to adequately oversee the process and ensure that the reasons for removal of each U.S. Attorney were supportable and not improper.?

It also singled out for blame Mr. Gonzales?s chief of staff, Kyle Sampson, who supervised the firings. The report said he did not review formal evaluations of the attorneys? performance, nor did he consult department officials who were most knowledgeable about their performance.

Mr. Sampson, the report states, ?also bears significant responsibility for the flawed and arbitrary removal process.?

The firings were ?unsystematic and arbitrary, with little oversight by the Attorney General, the Deputy Attorney General, or any other senior Department official,? the report continues. Improperly, the nine U.S. attorneys were not given an opportunity to address concerns about their performance, nor were they given the reasons for their removal.

In addition, Mr. Gonzales, Mr. McNulty, Mr. Sampson, and other officials failed ?to provide accurate and truthful statements about the removals and their role in the process,? the report states.

The report?s lead authors ? Glenn A. Fine, the department?s inspector general, and H. Marshall Jarrett, the counsel for the department?s Office of Professional Responsibility ? wrote that their investigation remains incomplete because of the refusal of certain key witnesses to be interviewed, including Karl Rove, the president?s former chief political adviser; Harriet E. Miers, the former White House counsel; Monica Goodling, the department?s former White House liaison; Senator Pete Domenici, Republican of New Mexico; and Mr. Domenici?s chief of staff, Steven Bell.

In addition, they wrote, ?the White House would not provide us with internal documents related to the removals of the U.S. attorneys.?

The dismissal that has drawn the most scrutiny is that of David C. Iglesias, who was fired as the United States attorney for New Mexico after he clashed with Republican officials over what they saw as his slow pursuit of Democrats in a corruption investigation. Several of the other fired prosecutors were also working on sensitive public corruption cases; critics have alleged that they were dismissed because they were unwilling to faithfully carry out the White House?s political agenda.

The report states that the most serious investigation that the inspector general was not able to fully investigate relates to the removal of Mr. Iglesias. It singles out his firing as a key reason why a counsel should be appointed to ?conduct further investigation, and ultimately determine whether the evidence demonstrates that any criminal offense was committed.?

The investigation reviewed several thousand electronic and hard copy documents, including documents the Justice department produced in response to Congressional investigations of the U.S. attorney removals. Investigators obtained access to and searched the e-mail accounts of numerous current and former employees in the Attorney General?s Office, the Deputy Attorney General?s Office, and other Justice departments, the report states.

While White House officials did not explicitly assert executive privilege as the reason they refused to hand over to investigators internal e-mail messages and other documents related to the firings, the White House Counsel?s Office stated they were protected from disclosure because such material would ?implicate White House confidentiality interests of a very high order,? the report states.