The ricin found in Las Vegas is almost certainly part of a deliberate plot of some kind; authorities continue to insist there was “no link to terrorist activity,” but now they’ve found firearms and an “anarchist cookbook.”

LAS VEGAS - As police tried to piece together how a rare, deadly poison ended up in a motel for transients, the 57-year-old man who could hold the key lay unconscious in a hospital.

Adding to the mystery, police said firearms and an “anarchist type textbook” were found in the same room where the ricin was discovered two days later.

Capt. Joseph Lombardo said at a news conference late Friday that the book was tabbed at a spot with information about ricin. Police found the firearms and books on Tuesday after a manager at the Extended Stay America motel called police upon discovering weapons, he said, without elaborating. After authorities seized the book and weapons, tests for ricin were conducted but came back negative, Lombardo said.

He said a 53-year-old friend or relative of the sick man contacted motel management on Feb. 22 to inform them about pets in the room.

Earlier Friday, police Deputy Chief Kathy Suey said the friend or relative found two vials of ricin on Thursday after going to the motel to retrieve the hospitalized man’s belongings. Authorities on Friday confirmed that the vials contained ricin. It was unclear how long the vials were in the unoccupied motel room, and whether they might have been overlooked when ricin tests were conducted on Tuesday. Lombardo did not address such questions during the brief news conference.

“The only positive tests (were) on the powder in question” in the vials, he said.

Authorities said there was no apparent link to terrorist activity, and no indication of any spread of the deadly substance beyond the vials. The 57-year-old man was the last to stay in the room, and has been in critical condition since calling an ambulance on Feb. 14 complaining of respiratory distress.

Authorities offered little more about the man’s identity: He left pets in the room and was not considered a suspect. A dog was found dead, but the animal had gone at least a week without food or water, Suey said.

UPDATE at 3/1/08 8:45:31 am:

The Las Vegas Review-Journal has obtained a DHS document with the name of the critically injured man: Guns, anarchy text found in room with ricin.

The Metropolitan Police Department reported one person has been injured by the biological agent. That man has been in critical condition at Spring Valley Hospital Medical Center for more than two weeks.

Police said the man is 57 years old and was staying in the suite at the Extended Stay America on Valley View Boulevard near Flamingo Road where the ricin was found.

Police have not identified the man, but a Homeland Security internal document obtained by the Review-Journal states that he is Roger Von Bergendorff.

The man placed an emergency call from the suite on Feb. 14, saying he was in respiratory distress and asking to be transported to a hospital, police said.