Did Obama know about the ATF gun smuggling operation?

Mexico is complaining to the U.S. because they were not informed of the ATF gun smuggling operation which allowed high powered ault weapons to be funneled to the mexican drug cartels. In an interview Obama said if Mexico didn't know it was because he didn't know. This operation involved the ATF and the DHS, two major entities of the Administration and lead to the death of an American Agent who was shot and killed by one of the weapons smuggled across. Did Obama know about the gun smuggling operation? If I were President and this happened without my knowledge there would have been some heads rolling.