The U.S. Justice Department's internal watchdog on Wednesday referred 14 employees, including senior official Lanny Breuer, for possible internal discipline in connection with a botched gun probe in Arizona.
A 471-page report was released following a 19-month review by the department's inspector general into "Operation Fast and Furious," which allowed about 2,000 potentially illegal firearms to cross the border into Mexico.
The operation raised the fury of U.S. gun-rights advocates and is a focal point for Republican criticism of President Barack Obama leading up to the Nov. 6 elections.
Mr. Breuer, an Obama appointee and the head of the Justice Department's criminal division, is cited in the report for not alerting his superiors in 2010 to flaws in a program similar to Operation Fast and Furious that was started during George W. Bush's presidency.
One of Mr. Breuer's aides, Jason Weinstein, whom the report also refers for possible disciplinary action, has resigned from the department, a spokeswoman said on Wednesday. Mr. Weinstein failed to question firearms officials about the questionable tactics they used, the report said.
Another senior official, Kenneth Melson, will retire from the Justice Department, the spokeswoman said. Mr. Melson was the acting director of the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives until 2011, when he was reassigned.
Fast and Furious came to light after the December 2010 shooting death of a U.S. Border Patrol agent, Brian Terry. Two guns that firearms agents attempted to track were found at the scene of Mr. Terry's death in rural Arizona.
The inspector general's report concluded there is "no evidence" that Attorney General Eric Holder, who heads the Justice Department, knew the details of Fast and Furious before they became publicly known in February 2011. Mr. Holder requested the internal review the same month.