PORTLAND - A grand jury has indicted a Multnomah Couny inmate for allegedly sending a threatening letter containing a white powder labeled 'anthrax' to a federal prosecutor.
The letter, part of a string of hoaxes, claimed to be tainted with deadly anthrax but turned out to be non-toxic.
According to court documents obtained by KGW, the FBI believes Andrew Barnett sent the threatening letter while in custody at the Multnomah County Detention Center. In the search warrant, an FBI agent said Barnett sent three letters to an assistant United States Attorney in downtown Portland.
The indictment also tied Barnett to "false information and hoaxes" involving white powder which turned out to be nothing toxic.
Between late April and early May at least six letters containing a white powdery substance were sent to buildings across Portland.
Background: Suspicious envelope at courthouse
On April 26, an office worker at the U.S. Attorney's office opened the envelope and found white powder folded in a blank piece of white paper. The envelope also contained a letter which encouraged the federal prosecutor to snort the purported anthrax and said, "I want you gone!!!"
The return address on the envelope was listed as "Andrew Barnett" at the Multnomah County Detention Center.
More: FBI investigates several suspicious envelopes
In a press release dated May 11, the FBI stated that police believed they had "stopped the sender or senders' ability to continue this stream of threats."
More: FBI says white powder letters 'stopped'
Court records show Barnett has a history of sending threatening mail, including letters sent to the Washington County Sheriff's Office in 2008.
