Watching Congressman Darrell Issa, Chairman of the Committee on Oversight and Government Reform, and Senator Charles Grassley, Ranking Member of the Senate Judiciary Committee go up against Eric Holder's Justice Department is like watching Golding's Piggy try to reason with Jack's bloodthirsty gang of sow-worshipping killers.

But instead of a conch shell, the two men are writing letters -- lots of letters demanding the most corrupt Attorney General in history answer for the murders of two federal agents and hundreds of Mexican civilians.

The latest Issa/Grassley inquisition, a letter sent to AG Holder on February 27, focuses on a third Texas straw purchaser with ties to the murder of ICE Agent Jaime Zapata.

Records indicate that ATF opened a case against Manuel Barba in June 2010,[6] approximately two months before he took possession on August 20, 2010, of the rifle which was later trafficked to Mexico and also used in the murder of Agent Zapata.[7]

Additionally, the documents show that ATF had indications in October 2010 that Barba was obliterating serial numbers on weapons, the possession of which would have been a prosecutable offense.[8]

At least as of December 13, 2010, ATF also was aware that Barba was still under indictment for a 2006 state case, and thus had been unlawfully receiving firearms while under indictment.[9] However, a warrant was not issued for Barba's arrest in this case until February 14, 2011.[10]

Last week CBS' Sharyl Attkisson reported on a second walked gun found at the scene of Agent Zapata's murder. Houston prosecutors and the DOJ didn't bother to tell Jaime Zapata's family their son was killed by a weapon sold to a drug trafficker under surveillance by their own government; a weapon which eventually ended up in the hands of the Zetas drug cartel believed to be responsible for Jaime's murder.

The Zapatas didn't find out anything until after Barba was sentenced to 100 months in prison on January 30, 2012.

Issa and Grassley followed up on Attkisson's most recent report with some pertinent questions concerning ATF's hands-off approach to Barba.

Why was Barba not arrested in October 2010 when ATF obtained audio evidence that Barba was obliterating serial numbers before trafficking weapons to Mexico?

Why was Barba not arrested in December 2010 when ATF knew he had been unlawfully receiving firearms from straw purchasers while under indictment?

The letter also addressed the similarities between Phoenix's Fast and Furious operation and the Houston scheme. ATF North Texas spokesperson Tom Crowley denied the same tactics were used in the Houston program. Crowley also indicated Barba's early arrest would have "jeopardized" their investigation making it difficult to catch the bigger fish.

Issa responded to Crowley's statement by pointing out both operations failed to stop the guns from getting into the hands of drug cartel members.

Yet failure to conduct surveillance of individuals known to be trafficking weapons to Mexico was a core problem with the tactics used in Fast and Furious.

Lack of surveillance is what allowed such firearms to reach the border. The same irresponsible tactic appears to have been used in this matter.

Issa and Grassley have taken on a stonewalling, lying gang of corruptocrats, but only a tiny fraction of the public has even heard of Fast and Furious. Will this "take a letter, Maria" strategy really break through the media blackout?

The flurry of letters is probably the only recourse the watchdogs have when dealing with out-of-control officials who won't follow the law. If this criminal mess ever goes to trial, the correspondence will provide a timely record of an Obama administration gun-walking scandal destined for the history books.

Read more M. Catharine Evans at Potter Williams Report