Investigators work a hazardous materials scene at the Extended Stay America motel in Las Vegas, where the deadly toxin ricin was found in a room. A man who had been staying at the motel has been hospitalized for two weeks in critical condition.

Las Vegas ? Firearms and an “anarchist type textbook” were found in the same motel room where several vials of the deadly toxin ricin was found, police said Friday.

The room was most recently occupied by a 57-year-old man who has been in critical condition with breathing problems at a hospital for more than two weeks.

Las Vegas police said there was no apparent link to terrorist activity, and no indication of any spread of the deadly substance beyond the several vials of powder found in a plastic bag in the man’s room on Thursday. But what the ricin was doing there remained a mystery.

A pinprick of ricin is enough to kill.

Capt. Joseph Lombardo said at a press conference late Friday that the book was tabbed at a spot with information about ricin. Lombardo did not give more information about the book or specify what kinds of weapons were found.

A friend or relative of the sick man found the vials after going to the Extended Stay America motel, several blocks west of the Las Vegas Strip, to retrieve his belongings, police Deputy Chief Kathy Suey said.

Tests by police homeland security officers, the Nevada National Guard and a laboratory in Las Vegas came back positive for ricin, she said. A cleanup of the motel has been completed, she added.

Seven people, including the man who found the ricin, the manager, two other motel employees and three police officers, were decontaminated at the scene and taken to hospitals for examination, but none have shown any signs of being affected by ricin, Suey said. All were released overnight.

“There is no information to lead us to believe that this is the result of any terrorist activity or related to any possible terrorist activity,” Suey said. “We don’t have any reason to believe any of it left the property.”

Suey said the manufacture of ricin is a crime, but it was not clear the substance found belonged to the man, who was hospitalized in critical condition Feb. 14 after summoning an ambulance to the motel and complaining of respiratory distress.

The man was unconscious and unable to speak, Suey said. “We don’t know an awful lot about him,” she said. “We don’t even know that it was him that was in possession of the ricin.” She said she could not say how much ricin was in the vials.

Cancer research is the only legitimate reason for anyone to have ricin, Evans said.

Ricin is made from processing castor beans, and can be extremely lethal. As little as 500 micrograms, or about the size of the head of a pin, can kill a human, according to the Centers for Disease Control and Prevention in Atlanta.

Castor beans also were found in the man’s room, officials said.