Support WBURBoston Bombings Bring Out The 'Crowdsleuthers'Alan GreenblattApril 18, 2013 ShareThis image shows the remains of a black backpack that the FBI says contained one of the bombs that exploded during the Boston Marathon. (FBI via AP)
This image shows the remains of a black backpack that the FBI says contained one of the bombs that exploded during the Boston Marathon. (FBI via AP)