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Danny Chan La, Deseret Morning News
Police cordoned off a Riverton home Saturday after vials of ricin were found in a Las Vegas motel room where a former resident of the home was staying. The FBI says there is no public danger at this time.

RIVERTON — Authorities have isolated a Riverton home as part of an investigation into vials of the deadly poison ricin that were found in a Las Vegas motel room.

The FBI confirmed to the Deseret Morning News on Saturday that two people involved in the investigation are from Riverton.

"These guys have a connection to Utah," FBI Special Agent Juan Becerra said. "The reason we're looking at this residence is, that's the lead that was sent to us. There is no public danger at this time. We've been able to isolate that location."

Roger Von Bergendorff, 57, who lived in Riverton until recently, has been hospitalized in Las Vegas since Feb. 14.

After Von Bergendorff became ill, his cousin, Thomas Tholen, went down to help him. The vials of ricin were found by Tholen, 53, who took them to the motel office of the Extended Stay America that Von Bergendorff was staying in when he fell ill.

Tholen, several motel employees and three police officers had to be decontaminated.

Las Vegas police said Von Bergendorff is unconscious, so they have been unable to communicate with him.

On Saturday, a cadre of authorities responded to a home near 13400 South and 3000 West. Two women there were reportedly put through a decontamination process. Salt Lake County Sheriff's Lt. Paul Jaroscak declined to comment, referring all questions to the FBI.

"We've been assisting them," Jaroscak said Saturday. "We'll continue to assist them."

Becerra said there is no immediate health threat in the Riverton area.

"There is no indication of any threat to the public or individuals residing in that area," he said Saturday.

Police, FBI and U.S. Homeland Security agents are trying to figure out how vials of ricin ended up in Von Bergendorff's motel room, located a few blocks from the Las Vegas Strip.

On Friday, Las Vegas Metro police revealed that guns, an "anarchist-type" textbook and castor beans — from which ricin is made — were also found in the room where the poison was discovered.

On Feb. 22, Tholen called the motel to say that a dog and two cats were in Von Bergendorff's motel room. The dog had to be euthanized because it was sick after going without food and water for more than a week.

"He loved his animals," said neighbor Tonya Rogers, who said Von Bergendorff had a German shepherd.

Rogers' husband, Tim, said Tholen has always been very friendly, but Von Bergendorff was aloof, never returning a neighborly wave or really speaking to others on their quiet suburban street. Until recently, neighbors said, Von Bergendorff lived in Tholen's home.

Neighbors said they do not believe the Tholen family would be involved in anything nefarious.

"Good LDS people," Karma Neider said of the Tholens. "Tom would give the shirt off his back to help you."

"Tom was just trying to help out his cousin," said Lisa Pardee.

Some described Von Bergendorff as an avid animal lover — so much so, that he was distraught after a beloved cat went missing.

Law enforcement and health officials in Nevada insist they have found no apparent link to terrorist activity.

The Centers for Disease Control says that as little as 500 micrograms of ricin — an amount that would be about the size of the head of a pin — could be enough to kill an adult if it were inhaled or injected. Ricin can kill within 72 hours of exposure. It has no antidote, but if a victim doesn't die within three to five days, he will typically recover after being treated with medications to minimize the effects of the poison, the CDC said.

The CDC has documented some reports that ricin was used in the Iran-Iraq war in the 1980s, and some of the deadly toxin was found in al-Qaida caves in Afghanistan.

In 1978, Bulgarian journalist Georgi Markov died in London after he was attacked by a man wielding an umbrella that is believed to have been rigged to inject a ricin pellet under his skin.

Contributing: Andrew Kirk, Deseret Morning News; Associated Press

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