Acting DOJ Inspector General Cynthia Schnedar would be wise to keep the results of her investigations into the alleged Dodson leak, Fast and Furious, and any other gunrunning investigations that may develop for as long as is practically possible. As Gerald Walpin discovered the hard way, the Obama administration isn't kind to inspector generals that are determined to do their jobs.

The Justice Department's inspector general has opened an investigation into possible retaliation against a whistleblowing agent at the Bureau of Alcohol, Tobacco, Firearms and Explosives, according to two people briefed on the inquiry.

Watchdogs are examining whether anyone at the Justice Department improperly released internal correspondence to try to smear ATF agent John Dodson, who told the House Oversight and Government Reform Committee last month that he repeatedly warned supervisors about what he called a reckless law enforcement operation known as "Fast and Furious."

"I've warned the administration several times not to retaliate against the whistle-blowers who speak to Congress," Grassley wrote in an email to NPR Thursday. "Unfortunately, there are indications that the administration leaked Privacy Act-protected documents to the press in an effort to discredit Mr. Dodson with half-truths even though those documents had been withheld from Congress. It's a very serious matter that should be thoroughly investigated."

The Justice Department blocked senior ATF leaders from cooperating with Congress in its investigation of the "Fast and Furious" weapons operation, ordering them not to respond to questions and taking full control of replying to briefing and document requests, the agency's top boss told congressional investigators.

Kenneth E. Melson, the embattled acting director of the Bureau of Alcohol, Tobacco, Firearms and Explosives, told Senate Judiciary Committee and House Committee on Oversight and Government Reform investigators during a secret interview designed to circumvent Justice Department attorneys that he was "sick to his stomach" when he learned about problems with the controversial operation.