An FBI investigator walks down a fire truck lADDER with a bag from the top of a building at the corner of Boylston Street and Fairfield Street Wednesday April 17, 2013, in Boston. Investigators in ... more 
An FBI investigator walks down a fire truck lADDER with a bag from the top of a building at the corner of Boylston Street and Fairfield Street Wednesday April 17, 2013, in Boston. Investigators in white jumpsuits fanned out across the streets, rooftops and awnings around the blast site in search of clues on Wednesday. (AP Photo/Julio Cortez) less 
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Associated Press | Photo By Julio Cortez
Wed, Apr 17, 2013 4:09 PM EDT