WASHINGTON — The Justice Department’s inspector general on Wednesday issued a scathing critique of federal officials for their handling of the botched gun-trafficking case known as Operation Fast and Furious, but essentially exonerated Attorney General Eric H. Holder Jr., whom many Republicans have blamed for the scandal.

In a long-awaited report, the inspector general, Michael E. Horowitz, laid primary blame on what he portrayed as a dysfunctional and poorly supervised group of Arizona-based federal prosecutors and agents of the Bureau of Alcohol, Tobacco, Firearms and Explosives, describing them as “permeated” by “a series of misguided strategies, tactics, errors in judgment and management failures” that allowed a risky strategy to continue despite the danger to public safety.

The long-running controversy over Operation Fast and Furious, which ran from late 2009 to early 2011, stemmed from the fact that the A.T.F. officials directing it did not act swiftly to seize illegal weapons because they hoped to bring a bigger case against the organizers of a gun-smuggling network linked to a Mexican drug gang. The officials eventually lost track of hundreds of weapons, including two that were found near the site of where a Border Patrol agent, Brian Terry, was killed in a shootout.

The 471-page report is likely to be the closest definitive accounting of the operation, which has been the source of continuing confrontation between Congressional Republicans and the Obama administration, including a House vote to cite Mr. Holder for contempt in June.