John Tlumacki/Globe Staff
Investigators were combing through the aftermath of the deadly Boston Marathon terrorist attack Tuesday.
John Tlumacki/Globe Staff
Two people stood above 755 Boylston St.
John Tlumacki/Globe Staff
A wide view of the scene Tuesday.
John Tlumacki/Globe Staff
The scene outside of Marathon Sports, the site of the first bomb explosion.
John Tlumacki/Globe Staff
Police tape blocked off access to the area.
MATTHEW CAVANAUGH/EPA
A woman looked down Boylston Street Tuesday, toward the finish line of the Boston Marathon and the site of deadly bombings a day earlier.
MATTHEW CAVANAUGH/EPA
A Boston Police officer stood on Boylston Street on Tuesday.
Bill Greene/Globe Staff
Boston Police Commissioner Edward Davis spoke along with other local and federal officials Tuesday morning.
Elise Amendola/Associated Press
Senator Elizabeth Warren, Boston Mayor Thomas M. Menino, Governor Deval Patrick, and FBI special agent in charge Richard DesLauriers spoke at the press conference.
Susan Walsh/Associated Press
Speaking Tuesday afternoon at the White House, President Obama said, "We do not know whether this is an act of an organization, or an individual, or individuals."
Darren McCollester/Getty Images
A military police officer checked the identification of a man on Massachusetts Avenue on Tuesday morning.
Ex-Probation chief acquitted in first of two trials
