Congressional Republicans are trying to expand the scope of questions over the disastrous ATF gun-sting operation “Fast and Furious” to Homeland Security Secretary Janet A. Napolitano, asking her why she never investigated even after suspected guns showed up at the scene of a dead U.S. Border Patrol agent.

Having repeatedly excoriated Attorney General Eric H. Holder Jr., who Republicans said either knew or should have known about the gun-walking operation, party lawmakers this month have turned attention to Ms. Napolitano, saying she also should have asked questions once two AK-47s sold as part of the operation were found at the scene of the December shooting death of Agent Brian A. Terry.

“People on the ground knew that he was gunned down with “Fast and Furious” weapons. Three months went by, what did you do between December and February to find out the details about his loss of life?” Rep. Darrell E. Issa asked Ms. Napolitano on Wednesday at a HouseJudiciary Committee hearing. “Aren’t you outraged here today that you – if you were not informed – that you were not informed that weapons allowed to walk into drug dealers’ hands had killed one of your agents, and during those three months they kept it from you?”