FBI agents arrested a suspect in the case of the ricin found in the Las Vegas hotel, said FBI spokesman Richard Kolko according to CNN.com.

The man identified as Roger Von Bergendorff was the one that rented the room at the Extended Stay America, the hotel where agents found the deadly substance and some guns.

The 57-year-old man, who was hospitalized since 14 Feb with respiratory ailments and failing kidneys probably caused by exposure to the toxic substance, was charged with one count of possessing a biological toxin and two counts of possessing unregistered firearms.

The FBI put him under arrest after he was released from the Las Vegas hospital where he recovered from the ailments.

When they searched the hotel room, FBI agents found "an Anarchist's Cookbook, a collection of instructions on poisons and other dangerous recipes, including instructions on the preparation of ricin," and also two semiautomatic pistols, a rifle and a pistol with a silencer according to the press release from the Department of Justice.

Bergendorff was scheduled to appear in court at 3 p.m. on Wednesday.

The protein ricin is a toxin extracted from the castor bean (ricinus communis) and is highly lethal. Ricin has an average lethal dose in humans of 0.2 milligrams (1/5,000th of a gram), but in proper doses, ca be used in treating cancer.

Bergendorff has staid at the hotel where the deadly substance was found for an undisclosed period of time. One of the man’s relatives entered the room to retrieve the man’s belongings when he was in hospital and discovered the vials of white powder and showed it to the hotel’s manager.