The investigation into who was responsible for Monday’s terror attack at the Boston Marathon is underway. New details about the bombs have begun to emerge: The FBI says they were likely fashioned out of pressure cookers filled with nails and ball bearings and carried in nylon backpacks. But the investigation is in its infancy: No suspects are in custody, no motive is known, and the FBI is asking for tips.
A letter sent to Sen. Roger Wicker (R-MS) tested positive for the deadly toxin ricin. It was intercepted in the field and never reached the U.S. Capitol, and the senator and his office were never in danger.









