FBI: Mississippi Man Arrested as Suspect in Ricin Letters Sent to Obama

As authorities investigate three questionable packages discovered in Senate office buildings, reports of suspicious items also arrive from at least three senators' offices in their home states.

A man was arrested Wednesday, accused of sending letters to U.S. President Barack Obama and a senator that tested positive for the poison ricin and set the U.S.-capital on edge a day after the Boston Marathon bombings.