A dust mask and other items seized from the martial arts studio of a Mississippi man charged with sending poison-laced letters to President Barack Obama and two other public officials tested positive for ricin, according to a court document released on Tuesday.
Records seized by the FBI also showed that Tupelo martial arts instructor Everett Dutschke ordered castor bean seeds, used to make ricin, from eBay, FBI Special Agent Stephen Thomason said in an eight-page affidavit.
Dutschke is expected to appear in U.S. district court in Oxford, Mississippi, for a detention hearing on Thursday.
Contacted by Reuters, Dutschke's attorney, public defender George Lucas, declined to comment.
Soon after the seeds were delivered to Dutschke's home address, someone using his laptop computer downloaded a publication on safe handling and storage of the poison, Thomason stated.
An agent last week retrieved the contaminated dusk mask from a trash can near Dutschke's former taekwondo studio. Traces of ricin were also discovered on four items found at the studio, including liquid removed from a drain and a filter containing items vacuumed from the studio floor, the affidavit said.
Dutschke, 41, was arrested at his Tupelo home on Saturday following searches of his home and a former business as part of the ricin letter investigation.
He was later charged with "developing ... and possessing" ricin and "attempting" to use it "as a weapon," according to a Department of Justice statement.
If convicted, Dutschke faces maximum possible penalties of life imprisonment and a $250,000 fine.
The ricin-laced letters, addressed to Mississippi Senator Roger Wicker, as well as Obama, were retrieved earlier this month at off-site mail facilities before reaching their intended victims. A Mississippi state judge also received a ricin-laced letter.
Discovery of the letters fueled more national anxiety in the days after the bombing at the Boston Marathon.
(Reporting by Emily Lane; Writing by David Adams; Editing by Phil Berlowitz and Steve Orlosky)