The FBI says four similar letters were postmarked the same day , with similar ink . Comment: The FBI is looking for a letter that was directed to the CIA . Tests are being conducted on the letter sent to Fairchild Air Force Base to determine whether it -- like those other three letters -- contained ricin . All five letters are believed to have been sent from Spokane around May 13 .
The FBI says four similar letters were postmarked the same day , with similar ink . Comment: The FBI is looking for a letter that was directed to the CIA . All five letters are believed to have been sent from Spokane around May 13 .