The ATF and/or the US Attorney's office in Phoenix allowed at least 1,400 guns to be smuggled from the US to drug cartels in Mexico, ostensibly so they could track the guns up the food chain and then make big arrests. Instead, and tragically, Border Patrol Agent Brian Terry was murdered. One of the weapons nearby was indeed one that US law enforcement had allowed to pass through to Mexico. Other weapons have apparently been linked to other crimes.

The acting head of ATF, Kenneth Melson, was abruptlyreassigned and US Attorney General for the District of Arizona, Dennis Burke, resigned.  Melson testified to Congress that he knew nothing about the gun-walking and that it was run out of a special task force in the Phoenix Attorney General's office. You do see where this is going, right? The various agencies will all try to blame each other. This could well lead to paralysis and mistrust between law enforcement agencies as coping with it takes increasing amounts of time. Indeed, the Weekly Standard says it appears multiple agencies - including DEA, FBI, and Homeland Security - were involved.  If so, then things will get very nasty indeed.

It gets worse.   Burke may also have been involved in another smuggling attempt. This one involved parts for hundreds of grenades. The suspect, Jean Baptiste Kingery, was arrested in Arizona, only to be released hours later. ATF agents wanted him held but were overruled by the Attorney General's office. Kingery was recently arrested in Mexico, with parts for yet hundreds of more grenades.

So how many guns and grenade parts have US law enforcement allowed to pass to drug cartels? More to the point, isn't this against the law? It shouldn't matter if law enforcement wanted to do a sting and track the weapons to cartel leaders. They did in fact allow guns to be smuggled into Mexico. This is not only wrong, it's also, well, crazy. We're supposed to be cooperating with Mexico yet they weren't told. And just how did they plan to track the weapons to cartel bosses? Inquiring minds want to know.

Well, it's more than just inquiring minds that want to know. So doSen. John McCain and other lawmakers. Expect inquiries, lots of them. At least one Arizona blogger thinks Burke and others may want to lawyer up. The Department of Justice has removed all cases related to the gun-walking from the Arizona Attorney General's office.

US Attorney General Eric Holder did not point blank deny that those at high levels knew, instead saying:

"The notion that this reaches into the upper levels of the Justice Department is something that at this point I don't think is supported by the facts and I think once we examine it and once the facts are revealed we'll see that's not the case."

Three White House staffers received emails briefing them about the gun-walking. A senior administration official says this proves no one knew about the investigative techniques being used. But that's not what's at issue. A briefing would necessarily contain operational details.

What did all the players know and when did they know it? We will no doubt be finding out.