On April 16, 2013, FBI Director Robert Mueller updated President Barack Obama on the explosions that occurred in Boston the previous day. Seated, from left, are Homeland Security Secretary Janet Napolitano; Deputy National Security Advisor Tony Blinken; National Security Advisor to the Vice President Jake Sullivan; Attorney General Eric Holder; Assistant to the President for Homeland Security and Counterterrorism Lisa Monaco; and Chief of Staff Denis McDonough. Official White House Photo by Pete Souza