NBC News reports that federal agents have arrested a Mississippi man in connection with the mailing of letters to President Barack Obama and U.S Senator Roger Wicker (R-Miss) that initially tested positive for the poison ricin. The suspect has been identified by as Paul Kevin Curtis of Corinth, Miss. FBI Special Agent in Charge Daniel McMullen told the Associated Press that the man was arrested Wednesday.
Federal officials told NBC that both letters, postmarked April 8, 2013 and sent from Memphis, Tenn., included an identical phrase, "to see a wrong and not expose it, is to become a silent partner to its continuance." Both letters were signed: "I am KC and I approve this message."
CBS News reports that the ricin sent to the president and Sen. Wicker was "low grade" and "less than one percent toxin."
A federal official told NBC that the sender of the letters, "may have stumbled onto something," but they have yet to discover whether he actually made full-blown ricin toxin.
Update: Wednesday, April 17, 2013 - 8:28 p.m. ET:
Update: Wednesday, April 17, 2013 - 8:41 p.m. ET: