The FBI has identified a Mississippi man suspected of mailing letters containing poisonous ricin as 45-year-old Paul Kevin Curtis.
FBI Special Agent in Charge Daniel McMullen said Curtis was arrested Wednesday afternoon at his apartment in Corinth, near the Tennessee state line about 100 miles east of Memphis.
Authorities still waited for definitive tests on the letters sent to President Barack Obama and Sen. Roger Wicker, R-Miss.
An FBI intelligence bulletin obtained by The Associated Press said those two letters were postmarked Memphis, Tenn.
Curtis has been charged with threatening Obama, Wicker, and a judge in Mississippi. If convicted, he could face up to 15 years in prison.
An affidavit says the letters told the recipients: "Maybe I have your attention now even if that means someone must die."