President Barack Obama meets with members of his national security team to discuss developments in the Boston bombings investigation, in the Situation Room of the White House, April 19, 2013. Pictured, from left, are: FBI Director Robert Mueller; Lisa Monaco, Assistant to the President for Homeland Security and Counterterrorism; Attorney General Eric Holder; Deputy National Security Advisor Tony Blinken; and Vice Persident Joe Biden. (Official White House Photo by Pete Souza)

President Barack Obama meets with members of his national security team to discuss developments in the Boston bombings investigation, in the Situation Room of the White House, April 19, 2013. Pictured, from left, are: FBI Director Robert Mueller; Lisa Monaco, Assistant to the President for Homeland Security and Counterterrorism; Attorney General Eric Holder; Deputy National Security Advisor Tony Blinken; and Vice Persident Joe Biden. (Official White House Photo by Pete Souza)