WASHINGTON — The Justice Department replaced three officials Tuesday who played critical roles in a flawed law enforcement operation aimed at major gun-trafficking networks on the Southwest border.

The department announced that the acting director of the Bureau of Alcohol, Tobacco, Firearms and Explosives and the U.S. attorney in Arizona had resigned and an administration official said a prosecutor who worked on the operation was reassigned to civil cases.

The operation, known as Fast and Furious, was designed to track small-time gun buyers at several Phoenix-area gun shops up the chain to make cases against major weapons traffickers. It was a response to longstanding criticism of ATF for concentrating on small-time gun violations and failing to attack the kingpins of weapons trafficking.

A congressional investigation of the program has turned up evidence that ATF lost track of many of the more than 2,000 guns linked to the operation. The Justice Department inspector general also is looking into the operation at the request of Attorney General Eric Holder.

The operation has resulted in charges against 20 people and more may be charged.

Kenneth Melson will be replaced as ATF’s acting chief by B. Todd Jones, the U.S. attorney in Minnesota.

With Republicans in Congress and the department bickering over the investigation, Melson finally testified recently to Hill investigators in private. He said his department superiors “were doing more damage control than anything” and trying to keep the controversy away from top officials.

The moves are the latest and most significant effort by the Justice Department to address the controversy. In earlier personnel changes, three ATF agents were laterally transferred starting in May from operational positions to administrative roles.

ATF intelligence analyst Lorren Leadmon testified before the House Oversight and Government Reform committee last month that of more than 2,000 weapons linked to Fast and Furious, some 1,400 have not been recovered.

Republican Rep. Darrell Issa of California, chair of the House panel, said in a statement that “the reckless disregard for safety that took place in Operation Fast and Furious certainly merits changes.”

The strategy behind Fast and Furious carried the risk that its tracking dimension would be inadequate and some guns would wind up in the hands of criminals in Mexico or the U.S. and be used at crime scenes — which did happen to some of the guns.

In testimony to congressional investigators, Melson said that in at least one instance ATF agents did not intercept high-powered weapons when they could and should have.

But congressional hearings also brought complaints from ATF agents about the difficulty of arresting straw purchasers at the time of sale. More than half a dozen law enforcement officials who testified in the congressional probe warned that penalties for illegal straw purchases are completely inadequate — with the result that U.S. Attorneys’ offices often decline to prosecute illegal straw purchasing cases.

Printed on Wednesday, August 31, 2011 as: Three officials attached to ATF's botched gun-trafficking operation are replaced.