Article Photos: FBI issues photos of 2 suspects in Boston bombing 32/43

Investigators inspect the roof of a building across the street from the area where a bomb exploded near the Boston Marathon finish line, Thursday, April 18, 2013, in Boston. Investigators in white jumpsuits fanned out across the streets, rooftops and awnings around the blast site in search of clues.  (AP Photo/Julio Cortez)