“Not only have you yet to provide us with any information or documents about this operation, but, months after ATF shut down the operation, you have refused to respond at all,” the letter states.

House Oversight Committee chairman Darrell Issa (R., Calif.), Senate Judiciary Committee ranking member Charles Grassley (R., Iowa), Rep. Robert Goodlatte (R., Va.), and Rep. Jim Sensenbrenner (R., Wis.) signed the letter.

Operation Fearless, named after an undercover store that ATF officials called “Fearless Distributing,” attempted to use the store as a front to buy and possibly sell firearms and to target criminals in undercover sting operations.

The store attracted consumers by “selling clothes, shoes, and drug paraphernalia” while making it known that they were interested in buying firearms, according to the Milwaukee Journal Sentinel, which broke the story in January.

The operation had numerous problems from the start, according to the Sentinel.

Auto parts and other objects were stolen from the store in October 2012. The store did not have a security system in place, resulting in criminals stealing $35,000 in merchandise, including a machine gun and handgun that have yet to be found.

The landlord of the property, who unknowingly rented the store to ATF, requested more than $15,000 in damages from the ATF. The ATF has thus far refused to pay.

The operation is part of ATF’s Violent Crime Impact Team (VCIT), which targets hot spots in certain cities to deter gun crime. The division has been criticized for being ineffective.

The situation in Milwaukee “raise[s] significant management issues relating to the oversight and management of the ATF field office and ATF headquarters,” according to a letter by Justice Department IG Michael Horowitz.

Officials are not only questioning the robberies that derailed Operation Fearless, but also the methods used by ATF officials.

The January letter asked 22 questions, including “were the weapons reportedly stolen from the unattached vehicle secured with any type of safety device/trigger lock?” and “if weapons were sold, who approved the plan to conduct these sales?”

“Congressional oversight of a clearly botched operation in necessary,” the letter states.

“Instead of welcoming the opportunity to get to the bottom of this matter and solve the problems within the bureau the led to it, you have instead chosen to ignore our oversight request and attempt to handle the matter internally without any openness or transparency.”

“The ATF’s failure to respond to our initial inquiry is unacceptable,” Sensenbrenner said in a statement to the Free Beacon. “The agency has a lengthening history of inexplicable investigations. They need to answer for this failed sting operation and soon.”

ATF has received the letter and it is “with officials being reviewed,” an ATF official told the Free Beacon.

CBS News has learned that one weapon recovered from the area of the crime scene was originally purchased by federal agent George Gillett, an Alcohol, Tobacco and Firearms (ATF) manager who was faulted by the Inspector General in Operation Fast and Furious.

Gillett was the Assistant Special Agent in Charge of ATF Phoenix when Fast and Furious started. The recovered weapon is a so-called FN Herstal pistol nicknamed a “cop-killer” because of its designation as a “weapon of choice” for Mexican drug cartels.

The Inspector General has opened an inquiry to determine how his firearm “got into the hands of suspected cartel members.” The agent told CBS that he had sold the weapon on the Internet last year.

The DOJ’s inspector general issued a report that fingered 14 individuals for inappropriate handling of Operation Fast and Furious. Two of them, former Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) Director Kenneth Melson and Deputy Assistant Attorney General for the Criminal Division Jason Weinstein, resigned Wednesday.

Politico wrote, citing the report:

“Our review of Operation Fast and Furious and related matters revealed a series of misguided strategies, tactics, errors in judgment, and management failures that permeated ATF headquarters and the Phoenix Field Division, as well as the U.S. Attorney’s Office for the District of Arizona,” Inspector General Michael Horowitz writes in the report. “Individuals ranging from line agents and prosecutors in Phoenix and Tucson to senior ATF officials in Washington, D.C. … bore a share of responsibility for ATF’s knowing failure … to interdict firearms illegally destined for Mexico, and for doing so without adequately taking into account the danger to public safety that flowed from this risky strategy.”

Attorney General Eric Holder viewed the report as clearing him from any associated guilt with the scandal, as “The investigators found Holder didn’t know about the operation or its controversial tactics until after the scandal emerged,” Politico wrote.

Holder chastised those who “were so quick to make baseless accusations before they possessed the facts.”

The report, according to Politico, “essentially clears Attorney General Eric Holder … of any wrongdoing or errors in judgment.”

Republicans vehemently disagree with this analysis.

Sen. Jon Kyl of Arizona—where boarder patrol agent Brian Terry was killed, setting off the scandal—said, “It’s obvious it’s one of those things where either way, the attorney general can be blamed for what happened. Either he didn’t know and should have, or he did and he hasn’t ‘fessed up to Congress.”

Rep. Darrell Issa, the chairman of the House Committee on Oversight and Government Reform, who spearheaded an investigation into the scandal, did not back down from his criticism of the Attorney General.

He said on Fox News, “Attorney General Holder didn’t ask the questions, didn’t read the memos … Eric Holder didn’t do his job.”

Weinstein, who served in the DOJ for 15 years, decried the Inspector General’s accusations in his resignation letter, declaring the accusation that he did not report the gun walking in Fast and Furious “demonstrably false.” He bemoaned the “dynamic of internal investigations of this nature” that result in singling out “someone … for blame.”

Holder’s reluctance to release documents related to the scandal resulted in Congress holding him in contempt in June.

“Choices and consequences means simply that if you make poor choices, that if you don’t abide by the rules, that if you don’t respect the chain of command, if you don’t find the appropriate way to raise your concerns to your leadership, there will be consequences, because we cannot tolerate—we cannot tolerate—an undisciplined organization,” Jones said in the video.

Some lawmakers and government accountability groups interpreted the words as a warning to employees considering blowing the whistle on corruption.

In a July 18 letter to Jones, Rep. Darrell Issa (R., Calif.) and Sen. Chuck Grassley (R., Iowa) wrote ATF employees must be “free and clear of agency interference or retaliation” if they choose to talk to Congress.

“Your ominous message—which could be interpreted as a threat—is likely to have a major chilling effect on ATF employees exercising their rights to contact Congress,” the two lawmakers wrote. “Therefore, it needs to be clarified.”

“On numerous occasions, we have stressed to ATF and the Department of Justice the importance of protecting whistleblower disclosures and preventing retaliation against whistleblowers,” they continued.

“The bureau needs to make up its mind whether it’s going to be supportive of employees trying to get its mission back on track, or if it’s going to snuff out dissent,” said Tom Devine, the legal director of the Government Accountability Project. “There doesn’t seem to be any consensus.”

Grassley and Issa spearheaded the investigation into “Operation Fast and Furious,” a flawed gun-walking scheme in which federal agents allowed thousands of firearms to be smuggled across the U.S. border and into the hands of Mexican drug cartels.

“What it appears to be is a not-so-veiled threat telling (ATF employees) not to do what they did to expose Fast and Furious,” Issa told Fox News. “He’s basically saying, ‘No, keep it in the chain.’”

Former ATF agent Jay Dobyns, who has been an outspoken critic of the agency’s leadership, said Jones’ video misrepresented the atmosphere at the agency toward whistleblowers.

“The problem is the whistleblowers I know have all played by the rules and presented complaints to first, second and third level supervisors, the Ombudsman’s office, Internal Affairs, the EEOC, the OIG and OSC, Congress, and finally the media,” Dobyns wrote on CleanUpATF.org, a forum created by fellow ATF whistleblower Vincent Cefalu.

“None that I am personally aware of immediately jumped [up] and put themselves in front of a reporter or camera. What Acting Director Jones does not discuss is the utter lack of interest when whistleblowers follow the rules. He talks as if the process is balanced but the truth is it is a one-way street. You get NO attention or concern until an executive is embarrassed in the media. Not even an acknowledgement of a complaint beyond a boilerplate email—thank you for your interest; we are very concerned; blah, etc.”

Grassley and Issa have previously voiced concern over retaliatory statements made against whistleblowers at the ATF. In a June 29 letter to the Inspector General, Grassley and Issa wrote that, according to eyewitness accounts, ATF Chief of Public Affairs Scot Thomasson vowed retaliation against agents who first disclosed the details of the scandalous Fast and Furious operation.

“All of these whistleblowers have axes to grind,” Thomasson allegedly said. “ATF needs to f—k these guys. We need to get whatever dirt we can on these guys and take them down.”

The Government Accountability Project’s Devine said his organization is working to promote legislation called the Whistleblower Protection Enhancement Act, which would strengthen protections for government employees who report misconduct.

The bill is currently in pre-conference negotiations between the House and the Senate, and he expects a final vote sometime in September, Devine said.

Devine said his organization has recently had positive experiences with ATF leadership resolving whistleblower complaints, but the July 9 video sent a contradictory message.

The Obama administration has been among the harshest in American history when it comes to targeting and prosecuting the whistleblowers that leak information, as well as the journalists who obtain that information.

Under President Obama, more Americans have been charged under the Espionage Act for leaking classified information than all previous administrations combined.

President Obama pledged to run the “most transparent administration in history” upon entering office.

In a statement to the Free Beacon, ATF spokesman Marc Willis said the video was addressed to all employees, senior and junior level, and was not meant as a threat.

“The excerpt in question was not intended to discourage those with protected disclosure from pursuing the full range of legal protections available to them in raising work-related concerns,” Willis said. “Acting Director Jones and the leadership of ATF respect the rights of all ATF employees. The ATF leadership has specifically reminded employees and supervisors of employees with protected disclosure rights, about their protections under federal law.”

The spokesman also said Jones has expanded opportunities for employees to report work-related concerns since his appointment and added more staff in its ombudsman office to handle complaints.

The ATF has traced more than 68,000 firearms recovered at Mexican crime scenes over the last four years back to the U.S., the agency said. The bureau released data on gun traces from Mexican crime scenes between the years of 2007 and 2011.

The ATF ran traces on nearly 100,000 weapons recovered in Mexico, meaning U.S. weapons accounted for roughly 68 percent of those traced.

The 68 percent figure is much less than previous estimates floated by the Obama administration and gun-control advocates, who claimed U.S. guns accounted for more than 90 percent of weapons in cartel violence.

“A demand for these drugs in the United States is what is helping to keep these cartels in business,” President Obama said in April 2009. “This war is being waged with guns purchased not here, but in the United States. More than 90 percent of the guns recovered in Mexico come from the United States, many from gun shops that line our shared border.”

But even the 68 percent figure only reflects the guns submitted by the Mexican government to the ATF for tracing. The Mexican government is not obligated to turn over weapons for tracing.

The effect of Operation Fast and Furious is also not taken into account in the ATF’s data.

The ATF allowed more than 2,000 guns to be “walked” across the U.S.-Mexican border by straw-purchasers and delivered to violent drug cartels between 2009 and 2010 as part of the controversial operation.

Guns linked to Operation Fast and Furious were linked to the murder of U.S. Border Patrol Agent Brian Terry in 2010. They have also been linked to hundreds of other violent crimes across Mexico.

The number of recovered guns traced back to the U.S. peaked in 2008 at 21,035. The number dropped to 6,404 by 2010, but more than doubled in 2011 to 14,504.

Republican investigators who have led congressional efforts to uncover more information about Fast and Furious said the ATF’s numbers were only more evidence of the Obama administration’s failure.

“The Obama Justice Department’s efforts to facilitate the transfer of thousands of weapons to Mexican drug cartels does not appear to have helped stop the flow of illegal weapons to Mexico,” a spokesperson for the House Committee on Oversight and Government Reform told the Free Beacon Thursday.

One figure not included in the ATF’s data was “time-to-crime”—the amount of time between when a firearm was purchased and when it was recovered at a crime scene.

An ATF document obtained by the Free Beacon in February revealed that, of the 20,023 guns recovered between 2006 and 2010 at Mexican crime scenes and traced back to U.S. purchasers, 15,995 had a “time-to-crime” of three or more years, with an average time of 15 years.

The significant time between purchase and recovery suggests the “flood” of guns depicted by the Obama administration is exaggerated.

A Justice Department report states “the recovery of a crime gun within 2 to 3 years after its initial purchase is considered a short time-to-crime and a significant trafficking indicator.”

Drug violence has killed more than 47,000 people in Mexico over the past six years.

“Time-to-crime” is the period between a firearm’s retail sale and law enforcement’s recovery of the firearm in connection with a crime. For comparison, the U.S. average time-to-crime over the same period was 10.5 years. The time-to-crime average provides information about how quickly guns are getting from U.S. gun stores and into the hands of cartels, an indicator of how pervasive trafficking is.

The lengthy interval between guns being registered and recovered suggests that the Obama administration’s claims that illegally purchased American guns are fueling violence in Mexico’s drug war are overblown.

A Justice Department report states “the recovery of a crime gun within 2 to 3 years after its initial purchase is considered a short time-to-crime and a significant trafficking indicator.”

A source at the ATF said there were several factors leading to the long time-to-crime average in the document. The number included the time it takes between when Mexican authorities recovered a firearm and when it was sent to the ATF for tracing, which in some cases took up to a year or more, the source said.

According to the ATF, many of the firearms included in the figures were also old. For part of the investigation, Mexican authorities gave the ATF a list to comb through of roughly 60,000 serial numbers of weapons involved in crimes.

The document was filed as part of the court record in the 2011 case National Shooting Sports Foundation v. Jones and was never intended for the public. Nevertheless, it sheds new light on gun trafficking across the U.S.-Mexican border.

It is widely accepted that illegal trafficking is arming Mexico’s violent drug cartels, but exactly how many of those guns are coming from the U.S. has been the subject of fierce debate.

The Obama administration and gun control advocates have depicted cartel violence in Mexico as being fueled by a sudden flood of illegal guns coming from the U.S.

“A demand for these drugs in the United States is what is helping to keep these cartels in business,” President Obama said in April 2009. “This war is being waged with guns purchased not here, but in the United States. More than 90 percent of the guns recovered in Mexico come from the United States, many from gun shops that line our shared border.”

Obama was referring to a 2009 Government Accountability Office report that concluded about 87 percent of firearms seized by Mexican authorities and traced in the last five years originated in the United States.

Critics say that Obama and gun control advocates who cited the report failed to mention that only 7,200 of the roughly 30,000 guns seized by Mexican authorities in 2008 were sent to ATF for tracing.

Scott Stewart, an analyst for global intelligence company STRATFOR, wrote that only 4,000 of those were traceable. Of those, 3,480 were linked back to the United States. Using those numbers, 12 percent of the guns confiscated in 2008 were positively traced to the United States.

A Fox news report put the percentage of guns traced back to the U.S. in 2007 and 2008 at 17 percent. FactCheck.org argued the number should be closer to 36 percent.

At a hearing of the House Oversight Committee Thursday morning, House Republicans accused Holder of stonewalling their investigation by refusing to release congressionally subpoenaed documents.

On Wednesday, the Justice Department rejected Oversight Committee Chairman Darrell Issa’s (R-Calif.) February 9 deadline for another batch of documents, saying it was “impossible” to meet because of its broad scope.

At the hearing, Issa shot back at the Justice Department, complaining that the department’s inspector general office had been given many more documents for its own investigation than the committee.

“We’ve been told…that [documents] are difficult and time-consuming to give us. And yet 10 times as many documents have been given to the inspector general,” Issa said. “More than three times as many people have been interviewed by the inspector general,” said Issa. “When is the primary investigative committee of the U.S. House going to have the same access as your, essentially, self-appointed inspector general has?”

Republicans also continued to press Holder on exactly when and how much he and his department knew about the operation. A committee report released hours before the hearing claims Justice headquarters “had much greater knowledge of, and involvement in, Fast and Furious than it has previously acknowledged.”

Operation Fast and Furious allowed nearly 2,000 firearms to be purchased by suspected straw buyers in the United States and smuggled over the border, into Mexico and the hands of violent drug cartels. The intention was to track the firearms, but ATF agents lost track of roughly 1,400 of the guns.

Two AK-47s connected to Fast and Furious were later found at the scene of U.S. border agent Brian Terry’s murder in December 2010, leading to the probe.

Terry’s family announced Wednesday they intend to sue the Bureau of Alcohol, Tobacco, Firearms and Explosives and the Justice Department for $25 million. Terry’s family said the ATF operation was “abominable, reckless, nonsensical.”

In his testimony, Holder defended the Justice Department’s handling of the operation, as well as his own performance. Holder even said he should be given credit for the positive changes he’s brought to the Justice Department.

“I should be held accountable for, certainly, my role—whatever I did or didn’t do in connection to the supervision of Operation Fast and Furious,” Holder said. “But I’m Attorney General of the United States, and I should be held accountable, perhaps even given some credit—imagine that, given some credit—for the things that this Department has done under my leadership.”

But Holder did say for the first time since the controversy began that those responsible for the decision to let the guns walk across the border will likely be dismissed, citing the ongoing investigation by the inspector general.

“Unless there’s some truly compelling circumstance, those people will be removed from federal service,” Holder said, adding that he expected the department would take such action in the next six months.

Committee Democrats derided the hearing—the sixth so far that Holder has testified at—as a politically charged “election-year witch hunt.”

“Mr. Chairman, although you deserve credit for exposing these operations over the last five years, we part ways in what we should do next,” said Rep. Elijah Cummings (D-Md.). “You now appear intent on escalating controversy and promoting unsubstantiated allegations in a campaign that looks more like an election-year witch hunt than an even-handed investigation.”

Rep. Lacy Clay (D-Mo.) asked, “Does the majority even attempt to avoid the appearance that this is nothing but a politically motivated attack?”

And Rep. Dennis Kucinich (D-Ohio) said he had prayed for Holder before coming to the hearing.

Democrats repeatedly argued that gun-walking operations had begun under the Bush administration. They also called for stricter laws prosecuting straw buyers and gun traffickers.

Furor over operation Fast and Furious has led more than 55 members of Congress to call for the resignation of Holder, and the GOP has even set up a website where one can sign a petition calling for President Obama to fire Holder.