Nearly a month after the thwarted Christmas Day bombing of an airliner headed for Detroit, Minnesota's two senators questioned top government officials Wednesday about holes in the nation's airport security infrastructure and ways to prevent a similar attack in the future

In a series of committee hearings mired in detailed logistics, lawmakers examined why several federal agencies failed to stop Nigerian Umar Farouk Abdulmutallab from boarding a plane though they had indications he was a potential threat.

Sens. Amy Klobuchar and Al Franken spoke with the director of the FBI and representatives from the State Department and the Department of Homeland Security during a Judiciary Committee hearing Wednesday morning. Klobuchar later questioned the Homeland Security Secretary Janet Napolitano at a hearing of the Commerce Committee, which holds the purse strings of the Transportation Security Administration.

Franken largely focused on why Abdulmutallab was not given extra attention at the airport, despite being on the government's broadest list of people with possible terrorist ties. The so-called "TIDE" list, which feeds into other lists of more imminent threats, is not checked by airport security officials.

Minnesota's junior senator argued that people on the TIDE list should receive more screening before boarding airplanes.

"I'm saying that this guy's name was in a database of 550,000 people," Franken said, referring to the TIDE list. "That name, given today's technology, can come up in an instant. And then all it needed to do was warrant either a pat down or a body scan and he would have been discovered."

During the Commerce hearing, Klobuchar asked Napolitano whether she believes full-body scanning technology would have prevented the Christmas Day attack. The security chief tiptoed around stating flatly that the machines would have caught Abdulmutallab, but noted that the technology is better than anything currently being used.

"In and of itself, no one technology, no one process, no one intel agency is the silver bullet here," Napolitano added. "It's layer, layer, layer, layer."

Klobuchar also asked witnesses about updating other intelligence sharing technology and improving the government's coordination with air carriers.

"The key for me is not as much this blame game … but how do we fix this going forward," Klobuchar said.