U.S. lawmakers will question senior security officials this week about whether the FBI mishandled information after interviewing Boston Marathon bombing suspect Tamerlan Tsarnaev about his six-month stay last year in the Russian provinces of Dagestan and Chechnya.
The FBI was tipped off by Russian officials that 26-year-old Tsarnaev, who was killed last week in a shootout with Boston police, may have had extremist ties. But the FBI did not identify him as a potential threat.
Senator Dianne Feinstein, who chairs the Senate Intelligence Committee, says her panel will try "to sort it out" during a closed hearing late Tuesday. The House of Representatives will also be briefed by security officials Tuesday and the full Senate later this week.
Tsarnaev's younger brother Dzhokhar is facing the death penalty if convicted on charges of using a weapon of mass destruction in connection with the bombings last week that killed three people and injured more than 200.
Meanwhile, Dzhokhar Tsarnaev is recovering from several gunshot wounds. His initial court appearance is set for May 30.
Attorney General Eric Holder said the charges against Dzhokhar Tsarnaev show "Those who target innocent Americans and attempt to terrorize our cities will not escape from justice." He added, "We will hold those who are responsible for these heinous acts accountable to the fullest extent of the law."
Authorities say they do not believe the brothers were affiliated with a larger terrorist network and that the two acted alone. Officials have not publicly revealed a motive for the attack.
The two suspects are ethnic Chechen immigrants who came to the United States as boys.