It’s not the crime, it’s the coverup, goes the old Washington cliché. In the case of the Fast and Furious gun-walking scandal, it’s both.

As Attorney General Eric Holder gets ready to face more congressional grilling Thursday, something’s clearly rotten at the Justice Department. The stench goes all the way to the top — to Holder.

Friday, the feds disclosed documents that show that despite Holder’s claim during congressional testimony that he’d only learned of F&F “a few weeks” earlier (a claim later amended to “a couple of months”), he has known (or should have known) about it all along.

That information came in a series of e-mails in which the former US attorney in Arizona, Dennis Burke, discussed the F&F’s first fatality, agent Brian Terry, with a Holder deputy. The e-mails were sent in the early hours of Dec. 15, 2010, the day Terry died of wounds received the day before in a shootout 18 miles inside the US border, near Nogales.

The deputy, Monty Wilkinson, responded: “Tragic. I’ve alerted the AG.”

Burke, an anti-gun fanatic whose appointment as US attorney in 2009 roughly coincided with the start of F&F, goes on to tell Wilkinson later that day: “The guns found in the desert near the murder of the BP officer connect back to the investigation we were going to talk about — they were AK-47s purchased at a Phoenix gun store.”

That’s right. The government’s top law-enforcement officer has been turning a blind eye to a cancer in his department for more than a year....