( CNN ) -- A federal grand jury indicted a man arrested last week in connection with a mysterious case of exposure to the deadly biological agent ricin , prosecutors said . Authorities found ricin , weapons and an anarchist manual in Roger Von Bergendorff 's Nevada hotel room . Roger Von Bergendorff , 57 , was indicted on charges of possession of a biological toxin , possession of unregistered firearms and possession of firearms not identified by serial number , said Natalie Collins , a spokeswoman for the U.S. attorney 's office in Las Vegas , Nevada . Bergendorff was hospitalized for two months with suspected ricin poisoning , and was discharged before his arrest . His initial court appearance was last week , Collins said , and he did not enter a plea . An arraignment is scheduled for May 2 . Bergendorff was hospitalized in February complaining of breathing difficulties . Two weeks later , Thomas Tholen , a cousin who went to Bergendorff 's Las Vegas hotel room to recover his belongings , discovered what turned out to be ricin . Authorities also said a search of the room found four guns , the book `` Anarchist 's Cookbook , '' a collection of instructions on poisons and other dangerous recipes and castor beans , syringes and beakers . Ricin is extracted from ground-up castor beans . Tholen was charged earlier in April with failing to report the commission of a crime . A federal grand jury indicted him for allegedly concealing the knowledge that production and possession of a biological agent -- a felony -- was being committed . Bergendorff previously lived in Tholen 's home in Riverton , Utah , just south of Salt Lake City . After the ricin was discovered , the FBI searched that home as well as storage units Bergendorff used in Utah . Authorities said FBI agents searching the storage units found castor beans , chemicals used in the production of ricin , a respirator , filters , laboratory glassware , syringes and a notebook on ricin production . If convicted as charged , Bergendorff would face a sentence of up to 30 years in prison . E-mail to a friend .
Roger Von Bergendorff indicted on ricin possession charges . Bergendorff had been hospitalized with suspected ricin poisoning . Authorities found ricin , guns in Bergendorff 's Nevada hotel room . Thomas Tholen , Bergendorff 's cousin , also faces charges .