Postal workers in Spokane, Washington, on Saturday retrieved a wayward letter suspected of containing the deadly poison ricin that vanished for several weeks after it was sent from Washington state to a CIA address that does not receive mail, the FBI said.
The envelope resembled four ricin-laced letters postmarked May 13 from Spokane that had addresses penned in red ink, FBI agent Frank Harrill, an agency spokesman, said in a statement.
Matthew Ryan Buquet, 38, of Spokane was charged last month with mailing a threatening communication in connection with one of those four letters, which was sent to a federal judge but intercepted by a court employee during a screening process.
Ricin, a highly lethal poison made from castor beans, can enter the body through ingestion, inhalation or injection.
A "determination will be made at some point" over whether to charge Buquet with sending any additional ricin-laced letters in the batch, Harrill said in a phone interview.
The letter addressed to the CIA arrived at a U.S. Post Office in Spokane as undeliverable, Harrill said. The FBI previously issued a warning about the letter and said it was addressed to a "location that does not receive mail deliveries."
It will be sent next to a bioforensic lab to determine whether it, too, contains ricin, as did the other four letters in the batch from Washington state, the FBI said.
The three others, other than the envelope sent to a federal judge in Spokane, were addressed to President Barack Obama, Fairchild Air Force Base in Washington state and a U.S. Post Office in Spokane, the FBI said. Investigators are not aware of any illnesses connected to the letters.
The FBI has said the case is not related to two other recent cases of ricin-tainted envelopes sent to elected officials.
Actress Shannon Rogers Guess Richardson, of New Boston, Texas, was charged on Friday with sending ricin-laced letters to Obama and New York Mayor Michael Bloomberg. And martial arts instructor James Everett Dutschke, of Tupelo, Mississippi, was arrested on April 27 on suspicion of mailing three earlier such letters to the president and others.
The letters Richardson is accused of mailing contained menacing references to the U.S. debate on gun control.
The FBI has not disclosed the messages in the five letters sent from Washington state, and the bureau has not discussed a possible motive in the case.
(Reporting by Alex Dobuzinskis; Editing by Steve Gorman and Eric Walsh)