The deadly poison ricin was present in a letter sent from Spokane to Fairchild Air Force Base earlier this month, the FBI confirmed today.
Four other letters are believed to have been addressed in the same manner and sent at the same time to a federal judge, a post office, President Barack Obama and the Central Intelligence Agency. Two were intercepted by postal inspectors at the downtown Spokane post office on May 14.
Ricin had been previously confirmed in three of the letters; the one addressed to the CIA has not been recovered, FBI spokeswoman Ayn Sandalo Dietrich said. No one has been hurt by the letters.
The investigation is ongoing, Sandalo Dietrich said.
A Spokane man is in custody on a charge of making death threats in the letter addressed to U.S. District Court Judge Fred Van Sickle. Matthew Buquet, 38, was arrested May 22.