After the head of the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) was found to have known about his bureau's botched gun-tracking sting, Operation Fast and the Furious, a number of observers expected him to be forced out of government. But today, Kenneth Melson, the acting director of the ATF, was reassigned to a Justice Department post as senior adviser on forensic science in the Office of Legal Policy.

Announcing the shakeup, Attorney General Eric Holder praised Melson's "decades of experience" and thanked him for his "dedication to the department over the least three decades." Nowhere in the Justice Department press release was the mention of the congressional and internal DOJ investigations into the Fast and Furious operation, a failed effort to sell and monitor guns across the U.S.-Mexico border in the hopes of trapping Mexican drug cartel leaders, which ended up having tragic consequences as Reuters explains:

Authorities had hoped they would be able to follow the guns to cartel leaders, but ATF agents did not track the weapons after they were transferred from the initial buyer to others. Some agents have said they were not allowed to continue the pursuit.

Instead, numerous weapons from the operation, which began in late 2009 and ran through 2010, have shown up at crime scenes in Mexico and the United States.

U.S. Border Patrol agent Brian Terry died in a December 2010 shootout on the American side of the border and two guns found there have been traced to the sting.

Calling Melson's role into question, a congressional probe on the matter "uncovered emails that showed Melson was regularly briefed on the botched operation," reports The Los Angeles Times. In another reassignment, CBS News reports that "the Assistant U.S. Attorney in Phoenix, Emory Hurley, who... helped oversee the controversial case is also expected to be transferred out of the Criminal Division into the Civil Division." Here's who's crying foul about the ATF shakeup:

Texas Senator John Cornyn, as reported by The Los Angeles Times:

Simply transferring Melson within the Justice Department did not immediately sit well with some critics... "Instead of reassigning those responsible for Fast and Furious within the Department of Justice," Cornyn said, "Atty. Gen. Holder should ask for their resignations and come clean on all alleged gun-walking operations, including a detailed response to allegations of a Texas-based scheme."

California Congressman Darrell Issa, as reported by the Washington Examiner:

“While the reckless disregard for safety that took place in Operation Fast and Furious certainly merits changes within the Department of Justice, the Oversight and Government Reform Committee will continue its investigation to ensure that blame isn’t offloaded on just a few individuals for a matter that involved much higher levels of the Justice Department," Issa said in a statement. "There are still many questions to be answered about what happened in Operation Fast and Furious and who else bears responsibility, but these changes are warranted and offer an opportunity for the Justice Department to explain the role other officials and offices played in the infamous efforts to allow weapons to flow to Mexican drug cartels.  I also remain very concerned by Acting Director Melson’s statement that the Department of Justice is managing its response in a manner intended to protect its political appointees. Senator Grassley and I will continue to press the Department of Justice for answers in order to ensure that a reckless effort like Fast and Furious does not take place again.”

Iowa Senator Chuck Grassley, as reported by Talking Points Memo:

"There's a lot of blame to go around," said Sen. Chuck Grassley (R-Iowa). "As our investigation moves forward, and we get to the bottom of this policy, I wouldn't be surprised to see more fall out beyond the resignations and new assignments announced today."