BOSTON (AP) -- Lawmakers are asking tough questions about how the government tracked suspected Boston Marathon bomber Tamerlan Tsarnaev when he traveled to Russia last year, renewing criticism from after the Sept. 11 attacks that failure to share intelligence may have contributed to the deadly attack.
Senate Intelligence Committee Vice Chairman Saxby Chambliss, R-Ga., says it doesn't appear yet that anyone "dropped the ball." But he is asking federal agencies for more information about who knew what about the suspect.
[SPECIAL COVERAGE: BOSTON MARATHON TERROR ATTACK
Lawmakers attended a closed-door briefing on Capitol Hill with the FBI and other law enforcement officials on Tuesday.
Homeland Security Secretary Janet Napolitano told the Senate Judiciary Committee on immigration legislation that her agency knew about Tsarnaev's journey to his homeland. But Sen Lindsey Graham, R-S.C., says the FBI told him they had "no knowledge" of the trip.