On December 14, 2010, a firefight erupted in the Arizona desert. When the smoke had cleared, Customs and Border Protection Agent Brian Terry was dead, and the seeds of a scandal had been sown. Some of the rank and file of the Bureau of Alcohol, Tobacco, Firearms and Explosives (BATFE), often referred to as the ATF, began to grow concerned that a new development in Project Gunrunner probably had resulted in the death of Agent Terry.

First word of the incident began to appear on CleanUpATF.org , a whistle-blower website dedicated to "returning the integrity, accountability and decency to the ATF." Two Second Amendment advocates, Mike Vanderboegh of the blog Sipsey Street Irregulars and David Codrea, a writer at Gun Rights Examiner.com , became immediately aware of the posts, and their interest pushed them to collaborate and use their own sources within the ATF to confirm the allegations being made.

The pair independently corroborated the existence of a deviation from Project Gunrunner which they began to sardonically refer to as Project Gunwalker. Sources told them of the unstated policy to provide assault weapons to straw buyers, who would walk the guns over the border and sell them to members of the Mexican drug cartels for the purpose of manufacturing evidence.

One source of resistance to this development came from Darren Gil, then ATF attaché to Mexico, who felt strongly that the Mexican authorities should be made aware of the change in tactics. Gil brought his concerns to Special Agent in Charge of the Phoenix Office William D. Newell. Despite Gil's insistence, Newell refused to inform Mexico of the Bureau's intent. Frustrated and considering Newell's refusal to be a significant international policy error, Gil went to Newell's superiors in Washington. One can only speculate as to the conversations that took place, but Gil has since retired from the ATF.

With no further objections, the cynical plan allegedly was put into effect, and a string of subsequent events were unleashed. If played right, however, the Obama administration would get their "evidence," and the ATF could count on increased resources to pursue the very problem they were facilitating. That did not take into account the events that unfolded on the night of December 14 -- events which resulted in the death of Agent Terry.

Vanderboegh and Codrea relentlessly pursued the facts as presented to them by numerous and separate sources. They recognized that if true, the allegations would spell a serious breach of the public trust and the prospect of criminal activity within the ATF.

Finally, with facts in hand, they sought protection for their sources before going public. They approached several staff members on the Senate Judiciary Committee. They were directed from one person to the next. It was a struggle to ensure the safety of the agents putting their lives and careers on the line to expose the actions of the ATF. Eventually, Vanderboegh and Codrea obtained assurances that their informants would come under the whistle-blower protections offered by Senator Grassley of Iowa, ranking member of the Judiciary Committee. What follows is an excerpt of a letter from Grassley to Acting Director of the ATF Melson:

Members of the Judiciary Committee have received numerous allegations that the ATF sanctioned the sale of hundreds of assault weapons to suspected straw purchasers, who then allegedly transported these weapons throughout the southwestern border area and into Mexico. According to the allegations, one of these individuals purchased three assault rifles with cash in Glendale, Arizona on January 16, 2010. Two of the weapons were then allegedly used in a firefight on December 14, 2010 against Customs and Border Protection (CBP) agents, killing CBP Agent Brian Terry.

On January 30, 2011, there came word that the ATF in Phoenix, instead of helping Senator Grassley get to the bottom of the allegations, had begun to exert retaliatory pressure against agents suspected of blowing the whistle on the operation. The following is an excerpt from the subsequent letter sent from Grassley to Acting Director Melson upon hearing of the retaliation:

As you know, I wrote you on Thursday, January 27, regarding serious allegations associated with Project Gunrunner and the death of Customs and Protection Agent Brian Terry. Although the staff briefing I requested has not been scheduled, it appears that the ATF is reacting in less productive ways to my request. I understand that Assistant Special Agent in Charge (ASAC) George Gillette of the ATF's Phoenix office questioned one of the individual agents who answered my staff's questions about Project Gunrunner.