Federal agents have arrested a Dallas man on suspicion of allegedly conducting a hoax that involved mailing two white powder-filled envelopes to the IRS and Social Security Administration in Austin and Maryland.
Michael Wayne Patterson, 51, appeared before a federal magistrate Friday. He was taken into custody Thursday.
Authorities said they don't believe Patterson is responsible for the string of white powder letters known as the "Governors"' or "Embassy" mailings that were sent two years ago or the mailings that began in North Texas on Aug. 5.
According to an affidavit, an envelope containing a zip-locked plastic bag filled with an unknown white powder was sent to an Austin IRS facility Aug. 14. That building was immediately evacuated after IRS employees opened the envelope.
Two days later, on Aug. 16, workers at the main post office in Dallas discovered an envelope leaking white powder. That envelope was addressed to a social security office in Baltimore, Maryland.
Tests revealed that the powder was baking soda.
Prosecutors said handwriting and fingerprinting analysis showed Patterson had addressed both of the envelopes.
If convicted, Patterson faces up to five years in prison and a $250,000 fine per count.
It was not immediately known whether Patterson had an attorney. A message left by The Associated Press with the U.S. attorney's office on Friday evening was not immediately returned.
Authorities are still searching for the person or group who has mailed more than 250 letters since December 2008, including a batch sent to eight U.S. embassies and many governors' offices.
Those envelopes contained powder shown to be nontoxic and a single typewritten sentence in English that was unclear in meaning but that mentions al-Qaida, FBI Special Agent Mark White said.