KHQ.COM - Two letters, containing the toxin ricin, were seized from the downtown Spokane Post Office this week during a routine screening.
They were postmarked May 14th. One was addressed to a Federal judge in Spokane, the other to the Postal Union.
The FBI is in charge of the investigation and they are still trying to determine who sent the letters.
In a press release, The Associated Postal Workers Union confirmed the poison found was ricin, which can be deadly.
It's derived from castor beans and pretty easy to get your hands on.
This particular type of ricin was in a form that couldn't be inhaled or ingested easily.
The postal service says none of their employees were ever in danger of exposure and the letters have been sent to a lab for further testing.