LAS VEGAS -- A man hospitalized in Las Vegas earlier this year after being poisoned by ricin pleaded guilty Monday to possessing the deadly toxin, justice officials said.

Roger Von Bergendorff, 57, of Utah, admitted felony charges of possessing ricin and two unregistered firearm silencers in February this year, federal prosecutor Greg Brower said in a statement.

"Used improperly, ricin can be a very dangerous and deadly weapon," Brower said. "Fortunately, in this case, the ricin is not believed to have caused any harm to the public."

Von Bergendorff will be sentenced on November 3. Prosecutors have recommended he be jailed for 37 months.

The wheelchair-bound Von Bergendorff made no comment during Monday's hearing and neither defense of prosecution lawyers offered any further explanation as to why he had the ricin or what he intended to do with it.

Prosecutor Gregory Damm, who negotiated the plea arrangement, would only say: "There is no evidence to indicate any intent to target any individual or individuals with the substance."

Federal investigators have said previously they ruled out domestic terrorism as a motive.

Von Bergendorff was hospitalized in mid-February with symptoms corresponding to ricin poisoning. After arriving in critical condition, his condition eventually improved.

On February 26 authorities discovered ricin in his hotel room in Las Vegas, Nevada, as well as several guns and an anarchist manual with instructions on how to make various poisons.

Ricin is derived from the castor bean plant and can be dissolved in water, injected or sprayed. Lethal and easy to produce, ricin attacks the liver and the kidneys and has often been used in the world of espionage.

According to the US Centers for Disease Control and Prevention, 500 micrograms of ricin -- the size of a pin head -- is enough to kill an adult.