The FBI has arrested a man in Utah who authorities believe mailed letters to the Pentagon containing castor seeds — a key ingredient in the highly toxic substance ricin.
William Clyde Allen III of Logan, Utah, was arrested by agents with the Salt Lake City Division of the FBI.
Two envelopes mailed to the Pentagon earlier this week tested positive in a screening center for a hazardous substance. After conducting further tests, the FBI determined the envelopes contained castor seeds.
A third envelope sent to the White House tested positive for a hazardous substance at a mail screening facility. The FBI has not yet identified the substance involved.
Ricin is derived from castor seeds, but the seeds themselves are not dangerous. The FBI said the envelopes posed no threat.
The Military Times reports that Allen is a former enlisted sailor who spent four years in the Navy.
In April 2013, a series of letters that contained ricin and identical statements addressed to Sen. Roger Wicker, R-Miss., President Barack Obama and others were intercepted at mailing facilities. James Everett Dutschke of Mississippi received 25 years in federal prison and five years of supervised release for sending the letters.
The U.S. Attorney's Office said in a statement it expects to file a complaint Friday in federal court. Their statement did not offer further details, nor did a statement from the FBI.