WASHINGTON (CNN) -- A man at the center of a mysterious case of exposure to the deadly biological agent ricin has been arrested, FBI spokesman Richard Kolko said Wednesday.
Ricin was found in a room in this Las Vegas, Nevada, extended-stay hotel in February, police say.
Roger Bergendorff was taken into custody Wednesday morning in Las Vegas, Nevada, Kolko said.
Bergendorff, 57, was hospitalized with what was diagnosed as ricin exposure after the agent was discovered in his hotel room off the Las Vegas Strip.
Tests conducted by the FBI determined that the substance contained 2.9 percent active ricin. Its preparation was characterized as "crude," according to the U.S. attorney's office in Las Vegas.
According to a press release from the Department of Justice office, a search of Bergendorff's hotel room turned up "an 'Anarchist's Cookbook,' a collection of instructions on poisons and other dangerous recipes, including instructions on the preparation of ricin," two semiautomatic pistols, a rifle and a pistol with a silencer.
"FBI searches of Salt Lake City [Utah] storage units rented by Von Bergendorff resulted in the discovery of castor beans, various chemicals used in the production of ricin, a respirator, filters, painter's mask, laboratory glassware, syringes and a notebook on ricin production," the Justice Department release said.
Bergendorff is charged with possession of a biological toxin, possession of unregistered firearms and possession of firearms not identified by serial number, according to the U.S. attorney's office. If convicted of all charges, he would face a maximum penalty of 30 years in prison and a fine of $750,000.
Bergendorff is scheduled for an initial court appearance at 3 p.m. Wednesday.
It is illegal under federal law to possess a biological agent and toxin unless it is used for bona fide research or other peaceful purpose, U.S. Attorney Gregory Bower said in a written statement.
Bergendorff's cousin, Thomas Tholen of Riverton, Utah, was indicted by a federal grand jury in Salt Lake City this month, accused of failing to report production and possession of ricin.
Ricin is a poison that can be made from the waste of castor bean processing, according to the Centers for Disease Control and Prevention.
It can come in the form of a mist or pellet and can be dissolved in water or weak acid, the agency said.
Bergendorff was hospitalized February 14 in Las Vegas after he complained of difficulty breathing. He slipped into a coma and awoke March 14.
Bergendorff, 57, is an artist who neighbors said had lived in his cousin's basement before moving to Las Vegas. E-mail to a friend
CNN's Kevin Bohn, Karan Olson and Carol Cratty contributed to this report.