TUPELO, Miss. — The FBI confirmed on Tuesday that evidence taken from martial arts instructor James Everett Dutschke’s place of business tested positive for ricin. Along with making a stronger case against Dutschke—the primary suspect in the case of ricin-laced letters that were sent to President Barack Obama and two other officials—the test has brought further shame to his dojo.

“James-san had such promise,” said Dutschke’s chung sah nim, Dennis Conway of Ridgeland Taekwondo in Ridgeland, Miss. “A master never wishes to see his pupil wander from the way of the foot and the hand.”

According to the FBI’s affidavit, Dutschke bought 100 castor beans off eBay in late 2012, which can be used to create ricin. Letters containing crudely processed forms of the toxin were sent to the White House, Sen. Roger Wicker and Mississippi Judge Sadie Holland in April.

Gathering outside of Tupelo Taekwondo Plus on Wednesday, Dutschke’s students argued with each other, with some pledging loyalty to their kyo sah nim until his verdict is rendered, while others declared that they would become ronin, warriors without masters.

“We bring only dishonor to ourselves if we do not trust in our master’s claims of innocence. We bring dishonor to ourselves again if we do not trust that justice will follow an unbiased course,” said Tupelo Taekwondo Plus student Carson Gaines, 11.

Dutschke reportedly tried to frame 45-year-old Elvis impersonator and martial arts rival Kevin Curtis. A letter in one of the envelopes included the phrase “I am KC and I approve this message.” Police arrested then later released Curtis, but not before he mentioned that Dutschke might have been responsible.

“In taekwondo, one must always put the dojo first,” said Conway. “In this way, the tradition of taekwondo shall continue in Mississippi.”