"We also know this," Obama continued. "The American people refuse to be terrorized, because what the world saw yesterday in the aftermath of the explosions were stories of heroism and kindness and generosity and love, exhausted runners who kept running to the nearest hospital to give blood and those who stayed to tend to the wounded, some tearing off their own clothes to make tourniquets, the first responders who ran into the chaos to save lives, the men and women who are still treating the wounded at some of the best hospitals in the world, and the medical students who hurried to help."

The White House said Tuesday that the president was briefed by  Attorney General Eric HolderEric H. HolderEric Holder group to sue Georgia over redistricting Eric Holder to Trump: 'Taking a knee is not without precedent' Juan Williams: Momentum builds against gerrymandering MORE, FBI Director Robert Mueller, and Homeland Security Secretary Janet Napolitano, among other top aides. According to the White House, the Justice Department briefed the president on the collaborative efforts between federal and state law enforcement, while the Department of Homeland Security discussed intelligence sharing operation.