Washington (CNN) - If the new requirement that no-fly lists be checked by airlines every two hours had been in place, Times Square bombing suspect Faisal Shahzad would have been stopped before boarding a plane, Attorney General Eric Holder said Thursday.
Pressed by lawmakers at a Senate hearing, Holder said the requirement for airlines to check no-fly lists every two hours instead of 24 hours likely could have prompted authorities at the airport to apprehend Shahzad sooner.
Shahzad was arrested late Monday at New York's John F. Kennedy International Airport after boarding a flight bound for Dubai, United Arab Emirates. His final destination was Pakistan.
The Emirates plane had pulled away from the gate but was ordered back by customs officials. Shahzad was taken into custody.
Holder reiterated his statement to reporters Tuesday that he personally was "never worried" Shahzad would manage to escape, but acknowledged not everything went right.
"We were successful here, but am I satisfied? No," Holder told a Senate Appropriations panel.
Senators questioned Holder on the effective use of the terrorist watch list.
"Once again the watch list seems to be dysfunctional," panel chairman Sen. Barbara Mikulski, D-Maryland, said. "Who's in charge of making sure the watch list is used?"
Sen. Frank Lautenberg, D-New Jersey, pushed Holder on whether Shahzad should have been under investigation earlier following a visit to Pakistan.
"We are in the process of looking at files and indices to see what we knew about this man, and when we knew it," Holder said.
Holder also told lawmakers he finds "very worrisome" a law that allow loaded guns in vehicles at airports. Authorities found a loaded handgun in the glove compartment of Shahzad's car.