Mississippi martial arts instructor James Everett Dutschke is charged Saturday with possession of the biological agent ricin and with attempting to use it as a weapon.
The 41-year old was arrested following searches of his home and a former business as part of an investigation into ricin-laced letters sent to President Barack Obama and two other public officials.
If convicted, he faces maximum possible penalties of life imprisonment, a $250,000 fine.
He is expected to appear in the US District Court in Oxford, Mississippi, on Monday.
Earlier U.S. prosecutors dropped charges against another Mississippi man, who was released from jail after a search of his home revealed no incriminating evidence.
Dutschke has denied having anything to do with the ricin letters
