Federal agents discovered ricin in the Mississippi martial arts studio once used by the man charged with mailing letters containing the poison to President Barack Obama and two other public officials, according to a criminal complaint unsealed today.

Investigators also reported that the deadly toxin was found on a dust mask that FBI agents saw defendant James Everett Dutschke place last week into a “public garbage receptacle” in Tupelo, where he resides.

Other items dumped into the garbage by Dutschke (seen at right) included latex gloves and a box for a Black & Decker coffee grinder, an appliance that “could be utilized in the process of extracting ricin from castor beans.” In a sworn affidavit, FBI Agent Stephen Thomason added that “latex gloves and and a dust mask could be utilized as personal protective equipment while the castor beans are being crushed.”

The FBI affidavit also quotes an unnamed witness who recalled a conversation years ago with Dutschke, who reportedly spoke of his ability to manufacture a “poison” that could be placed in envelopes and sent to elected officials (who would die upon opening the envelopes).

A search of Dutschke’s Toshiba laptop revealed that, several months ago, someone using the computer downloaded two ricin-related publications, including “Standard Operating Procedure for Ricin,” which Agent Thomason noted, “describes safe handling and storage methods for ricin.”

During an interview last week, Dutschke “stated that he had never purchased castor beans, nor had he ever seen a castor bean.” However, eBay records subsequently obtained by the FBI showed that Dutschke late last year twice ordered castor bean seeds via the online auction site. He paid for both orders via PayPal, and the second batch of 50 seeds was delivered to his Tupelo residence.

Investigators began focusing on Dutschke after the case they had originally brought against another Mississippi man, Paul Kevin Curtis, collapsed. After his arrest, Curtis pointed the finger at Dutschke, a rival with whom he has had a contentious relationship.

Dutschke, 41, was arrested Saturday morning and charged with knowingly developing a biological agent for use as a weapon. He faces life in prison if convicted of the felony charge.

In addition to Obama, ricin-tainted letters were sent earlier this month to U.S. Senator Roger Wicker, a Mississippi Republican, and Sadie Holland, a Mississippi county judge. In 2007, Dutschke, running as the Republican nominee, unsuccessfully challenged Holland’s son in a state representative’s race.

Along with the ricin charge, Dutschke is facing trial on a three-count child molestation indictment returned last month. He has been accused of fondling a seven-year-old girl at the tae kwon do studio he previously operated.