Police said Von Bergendorff had a misdemeanor arrest several years ago but would release no other details until the ricin investigation is completed.
Suey said the suite was registered to the man, but she did not know how long he had stayed in the suite before his hospitalization.
According to the CDC, ricin can be made from waste left over from processing castor beans and can be used in cancer treatment.
"It would take a deliberate act to make ricin and use it to poison people," the CDC's Web site states. "Accidental exposure to ricin is highly unlikely."
As little as 500 micrograms of ricin, about the size of a pin head, could be enough to kill an adult.
Suey said police do not know whether the former occupant of the hotel suite manufactured or possessed the substance.
"Might he be a victim?" a reporter asked.
"That's possible," she said.
Suey said people could have any number of reasons for wanting to make ricin.
"It could be experimental just to see if they can," she said.
The last time Las Vegas police dealt with ricin was in 2003, when a 60-year-old man died after injecting himself with the poison.
Suey said the immediate concern of police after the ricin was found on Thursday was the public's health and safety.
"For the last 12 hours, our efforts have been on the containment and cleanup of the area," she said.
With that accomplished, Suey said, police were moving ahead with their investigation.
Naomi Jones, a spokeswoman at Spring Valley Hospital, said in a prepared statement Friday that all of the medical center's patients, visitors and employees are safe.
"The patient who has been exposed is not contagious to anyone else, as ricin has to be injected, ingested or inhaled," Jones said in the statement. "We are following the universal blood-borne pathogen protocols and cooperating with investigators at this time."
Las Vegas police notified hospital officials about the investigation involving the patient on Wednesday, according to the statement.
A statement released Friday by Desert Springs Hospital states that four people were taken to the facility Thursday evening for possible exposure to ricin "and are being tested and observed and will be discharged from the hospital once they are cleared by a physician per CDC protocols."
"While we cannot confirm whether the patients have been exposed to ricin, there is no risk of exposure to our patients, visitors and employees," according to the statement.
A statement from the Nevada Office of the Military states that 19 soldiers and airmen from the Nevada National Guard's 92nd Civil Support Team assisted Las Vegas police in the ricin investigation Thursday night. The team also assisted the Clark County Fire Department's hazardous materials team in the decontamination of the scene.