BOSTON – APRIL 16: (EDITORS NOTE: Retransmission with alternate crop; Best quality available) Investigators in white jumpsuits work the crime scene on Boylston Street following yesterday’s bomb attack at the Boston Marathon April 16, 2013 in Boston, Massachusetts. Security is tight in the City of Boston following yesterday’s two bomb explosions near the finish line of the Boston Marathon, that killed three people and wounding hundreds more. (Photo by Darren McCollester/Getty Images)