1/10U.S. President Barack Obama speaks at an interfaith memorial service for the victims of the bombing at the Boston Marathon at the Cathedral of the Holy Cross in Boston, Massachusetts, April 18, 2013.
U.S. President Barack Obama joins other public officials and religious leaders gathered in Boston for an interfaith memorial service for the victims of the Boston Marathon bombings earlier this week. The service, called the "Healing of our City," was held at Boston's Cathedral of the Holy Cross.
2/10People attend the interfaith memorial service at the Cathedral of the Holy Cross for the victims of the Boston Marathon bombing in Boston, April 18, 2013.
U.S. President Barack Obama joins other public officials and religious leaders gathered in Boston for an interfaith memorial service for the victims of the Boston Marathon bombings earlier this week. The service, called the "Healing of our City," was held at Boston's Cathedral of the Holy Cross.
3/10Nursing students Katie Robinson, left, and Megan Beach listen to a broadcast on their phones outside an interfaith service attended by President Barack Obama at the Cathedral of the Holy Cross, held in the wake of Boston Marathon explosions.
U.S. President Barack Obama joins other public officials and religious leaders gathered in Boston for an interfaith memorial service for the victims of the Boston Marathon bombings earlier this week. The service, called the "Healing of our City," was held at Boston's Cathedral of the Holy Cross.
4/10A memento of flowers in a running shoe rests at a makeshift memorial in Boston's Back Bay neighborhood, April 18, 2013, a few blocks from the finish line of the Boston Marathon.
U.S. President Barack Obama joins other public officials and religious leaders gathered in Boston for an interfaith memorial service for the victims of the Boston Marathon bombings earlier this week. The service, called the "Healing of our City," was held at Boston's Cathedral of the Holy Cross.
5/10Homeland Security Secretary Janet Napolitano testifies on Capitol Hill in Washington, April 18, 2013, before the House Homeland Security Committee. Napolitano says the FBI wants to speak with two men seen in at least one video from the Boston Marathon, but she says she isn't calling them suspects.
U.S. President Barack Obama joins other public officials and religious leaders gathered in Boston for an interfaith memorial service for the victims of the Boston Marathon bombings earlier this week. The service, called the "Healing of our City," was held at Boston's Cathedral of the Holy Cross.
6/10A line of investigators is form as they enter a building adjacent to one of the blast sites near the Boston Marathon finish line, in Boston, April 18, 2013.
U.S. President Barack Obama joins other public officials and religious leaders gathered in Boston for an interfaith memorial service for the victims of the Boston Marathon bombings earlier this week. The service, called the "Healing of our City," was held at Boston's Cathedral of the Holy Cross.
7/10Investigators inspect the area between the two blast sites near the Boston Marathon finish line, Thursday, April 18, 2013, in Boston. Boston remained under a heavy security presence, with scores of National Guard troops gathering among armored Humvees in
U.S. President Barack Obama joins other public officials and religious leaders gathered in Boston for an interfaith memorial service for the victims of the Boston Marathon bombings earlier this week. The service, called the "Healing of our City," was held at Boston's Cathedral of the Holy Cross.
8/10Local residents attend a candlelight vigil in the Dorchester neighborhood of Boston, Massachusetts, April 16, 2013, where eight-year-old victim Martin Richard lived.
U.S. President Barack Obama joins other public officials and religious leaders gathered in Boston for an interfaith memorial service for the victims of the Boston Marathon bombings earlier this week. The service, called the "Healing of our City," was held at Boston's Cathedral of the Holy Cross.
9/10Investigators comb through the post finish line area of the Boston Marathon at Boylston Street, two days after two bombs exploded just before the finish line, April 17, 2013, in Boston.
U.S. President Barack Obama joins other public officials and religious leaders gathered in Boston for an interfaith memorial service for the victims of the Boston Marathon bombings earlier this week. The service, called the "Healing of our City," was held at Boston's Cathedral of the Holy Cross.
10/10A worker returns a bag containing a runner's personal effects near the finish line of the Boston Marathon, after explosions killed three and injured more than 140 in Boston, April 16, 2013.
U.S. President Barack Obama joins other public officials and religious leaders gathered in Boston for an interfaith memorial service for the victims of the Boston Marathon bombings earlier this week. The service, called the "Healing of our City," was held at Boston's Cathedral of the Holy Cross.
