As Boston buries its dead, more evidence gathered - Article Photos 1/26

Boston Cardinal Sean O'Malley comforts Patty Campbell and her son, Billy, after a funeral for her daugher, Krystle Campbell, 29, at St. Joseph's Church in Medford, Mass. Monday, April 22, 2013. Krystle Campbell is one of three victims killed in the Boston Marathon explosions. (AP Photo/Elise Amendola)