FBI scientists at
the National Bioforensic Analysis Center determined that the fifth letter
located by postal workers on June 8, 2013 at the U.S. Post Office on W.
Riverside Avenue, Spokane, Washington contained active ricin toxin.
It had been
addressed to the Central Intelligence Agency. The letter was not delivered and
was returned to Spokane. The envelope was found unopened and not leaking any
The FBI and United States Postal Inspection Service (USPIS) are not
aware of any injuries or illnesses caused by any of the five letters recovered
during the course of this investigation.
No other suspect letters associated
with this investigation are known to be in the mail
previously, Matthew Ryan Buquet faces a one-count grand jury indictment for
mailing threatening communications, in relation to the letter sent to a Federal
District Court Judge in Spokane.
The investigation is ongoing, and we remain
focused on conducting it thoroughly, which will take an undetermined length of
time. The FBI and USPIS have no other details to release at present.