The man accused of sending ricin-laced letters to President Obama and others will appear in court today (Thursday).
A judge will decide whether 41-year-old James Everett Dutschke of Mississippi should remain in custody.
An affidavit unsealed Tuesday states laboratory tests showed five of the six samples taken from his former martial arts dojo tested positive for ricin.
In addition to President Obama, letters containing ricin were sent to Senator Roger Wicker of Mississippi and to a judge in Lee County, Mississippi.
Dutschke says he had nothing to do with the ricin letters.