The death of Customs and Border Protection Agent Brian Terry should have been an accident quietly disposed of in the silence of the Arizona desert. Everything was easily explained away, a CBP patrol came across a nefarious band of characters in the desert, a firefight erupted that left Agent Terry fatally injured. It could have been easy. The only trouble with the cover story was that the weapons held by the suspects were supposedly being tracked by the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives (BATFE) often referred to simply as the ATF.
How assault weapons sold with full knowledge of the ATF wound up in the hands of Mexican drug cartels has become the pertinent question in the scandal dubbed Gunwalker by David Codrea of Examiner.com a sardonic referral to the ATF's acknowledged project "Gunrunner." Codrea and Mike Vanderboegh of Sipsey Street Irregulars have been working diligently to break the story and shepherd congressional whistleblower protection to outraged ATF agents.
If one were to ask Assistant Attorney General Ronald Weich how this was allowed to happen, he might respond as he did to Senator Grassley's inquiries:
At the outset, the allegation described in your January 27 letter-that ATF "sanctioned" or otherwise knowingly allowed the sale of assault weapons to a straw purchaser who then transported them into Mexico-is false.
Further, Weich makes an accusation typical of the Obama Administration, wherein accusing the accuser is routine.
We also want to protect investigations and the law enforcement personnel who directly conduct them from inappropriate political influence. For this reason, we respectfully request that Committee staff not contact law enforcement personnel seeking information about pending criminal investigations. 
Assistant Attorney General Weich issued the denial and warning on February 4th, 2011 and raised the stakes in a high-level game of chicken with the Senate Judiciary Committee. Senator Grassley's response was quick and effective issuing this letter with attached corroboration of the charges.
Senator Grassley's letter contains these facts:
On January 16, 2010, Avila (the suspect purchasing the AK-47's from the gun dealer under knowledge of the ATF) bought three AK-47 variant Romanian WASR-10 assault rifles from the same dealer with the serial numbers 1983AH3977, 1979IS1530 and 1971CZ3775. ATF entered these weapons into the National Tracing Center's Suspect Gun Database three days later...
The letter continues:
After the shooting of CBP Agent Terry, law enforcement officials recovered from the scene two assault rifles. On December 16, 2010, ATF's trace results confirmed that serial numbers 1983AH3977 and 1971CZ3755 match two of the three rifles purchased by Avila and tracked by the ATF nearly a year earlier. In addition to these specific weapons, the indictment of Avila and other reference approximately 769 firearms. Of those, the indictment refers to the recovery of only about 103 weapons. So, where are the other approximately 666 weapons referenced in the indictment?
It seems clear from Senator Grassley's response that he is not impressed by Assistant Attorney General Weich's categorical denial or the warning to drop the investigation. In fact, the very last part of the letter is the most poignant as it includes a personal plea from Agent Terry's Stepmother, causing Senator Grassley to issue this plea:
The Terry family deserves answers. The whistleblowers have expressed a desire to honor Agent Terry's memory by disclosing this information. The Justice Department should do the same. The best way to honor his memory is to come clean.
What more can be said?
 February 4th letter from the U.S Department of Justice, Office of Legislative Affairs from Assistant Attorney General Ronald Weich to Charles E. Grassley, Ranking Minority Member Committee on the Judiciary.