Matthew Buquet has pleaded not guilty to sending threatening letters to President Obama, the CIA, Fairchild AFB and Federal Judge Fred Van Sickle that were tainted with Ricin.

Last week a grand jury indicted him on charges of developing, producing, and transferring a biological toxin, mailing a threatening communication to the president of the United States and mailing a threatening communication to a federal judge.

In all, five letters were mailed allegedly by Buquet to the Post Office in downtown Spokane, President Obama, the CIA, Van Sickle, Fairchild Air Force Base.

According to the indictment Buquet wrote in those letters, "We have a bomb placed, we are going to kill you! Hezbollah."

There's been no explanation as to why the letters were signed on Hezbollah's behalf.

All of the letters were later recovered.