If only Roger Bergendorff could say why vials of deadly ricin, guns and a copy of the "The Anarchist Cookbook" were found in his Las Vegas motel room.

Instead, the struggling graphic artist remained hospitalized Thursday, unconscious and on a ventilator, unable to describe how he and his beloved dog became the focus of a toxic mystery still puzzling investigators.

"At this stage of the investigation, he could be a perpetrator. He could be a victim. He could be both," said FBI agent David Staretz.

Bergendorff, 57, has been hospitalized since Feb. 14, when he summoned an ambulance to the Extended Stay America motel several blocks from the Las Vegas Strip, complaining of respiratory distress.

Authorities suspect Bergendorff was exposed to ricin, which is deadly even in minuscule amounts. But they cannot be sure because the poison breaks down in the body within days. Bergendorff was hospitalized for two weeks before the ricin was discovered in the motel room.

Family members and former neighbors in Southern California, Reno and the Salt Lake City area say they are mystified.

"I can say with confidence there was no intent for any kind of terrorist activity," said Erich Bergendorff, a younger brother who lives in Escondido, Calif. "I was asked by the FBI if he's affiliated with any group or if he would have been influenced by any group. I couldn't prove it, but I would be willing to bet that would not be the case."

Roger Bergendorff, whose middle name is Von, grew up in La Mesa, Calif., a bedroom community outside San Diego. He also lived in Huntington Beach, Calif., before moving at least six times from 1990 to 2007, according to public records and interviews with friends and family members.

Never married, he struggled with booze and bills. The recovering alcoholic declared both personal and business bankruptcy in the 1990s and suffered a heart attack in 1998, at age 48. He also was treated for depression, his brother said.

Bergendorff seemed to have constant money problems and sometimes overstayed his welcome when people tried to help.

He worked for slot machine maker International Game Technology in Reno from 2001 to 2004.

When he moved to Las Vegas, he told his family he was working on a contract designing graphics for another slot-machine company. That contract ran out, and he told his brother he planned to stay and wait for another job.

His brother said Bergendorff graduated in 1980 with a bachelor's degree from the Art Center College of Design in Pasadena, Calif.

"I don't think he felt he was creative enough," Erich Bergendorff said. "He really felt he had to work hard ... to keep up the standards that he had which were really quite high."

Friends and family members say Bergendorff was deeply saddened by the Jan. 27 death of his older brother, Fred, who had struggled with ALS, or Lou Gehrig's Disease.

Bergendorff was concerned he couldn't afford to travel from Las Vegas to Southern California for his brother's memorial service, family members said. He posted a Jan. 29 message online describing Fred Bergendorff as "the best brother you could have."

Roger Bergendorff also worried about his dog, Angel, who at 13 years old suffered health problems and needed eye drops four times a day, Erich Bergendorff said.

"Whatever he went to the hospital for, it was not suicide," Erich Bergendorff said. "There might have been an accident. He was very depressed about losing his brother and having financial difficulties and losing his job."

Family members didn't know until Feb. 21 that Roger Bergendorff was hospitalized. They reached a motel manager, who found the dog and two cats in Bergendorff's room and turned them over to the Humane Society.

With eviction looming, a motel employee went to the room again Feb. 26 and found guns in the room, police said. The employee contacted authorities, who retrieved the guns and William Powell's "cookbook" on how to assemble homemade bombs, marked at a section on ricin, Las Vegas police said.

Police found no ricin and tested the air, but found no contamination. They have not said what weapons were found.

Two days later, as cousin Thomas Tholen was collecting Bergendorff's belongings from the room, he turned over a plastic bag containing several vials of what turned out to be ricin powder to the motel manager. Authorities said castor beans, from which the ricin toxin is derived, also were found in Bergendorff's room.

Police and the FBI quickly denied any terrorism link, but have not explained why. Officials said Bergendorff could face state charges of possession of a controlled substance or more serious federal charges of possession and manufacture of ricin.

Ricin has no antidote, and can be lethal in amounts as small as the head of a pin. It prevents the body from synthesizing proteins and shuts down vital organs such as the liver, kidneys and heart.

"If you breathe it in, it would spread very rapidly through the bloodstream," said Andrew Ternay Jr., founder of the Rocky Mountain Center for Homeland Defense at the University of Denver.

"It's not the kind of stuff you use for anything except for poison," added Ternay, author of "The Language of Nightmares," a glossary of terms for chemical, biological and nuclear weapons.

The only legal use for ricin is cancer research.

In Riverton, Utah, where Roger Bergendorff lived before moving to Las Vegas, neighbors described him as a down-on-his-luck loner who lived for a time in a pickup truck camper with his pets.

John Walster let Bergendorff stay in the camper when he wore out his welcome at Tholen's home in the spring of 2006. He said Bergendorff stayed about three months before Walster asked him to leave in August 2006. When Bergendorff still didn't move out, Walster packed up his things and left them outside.

Bergendorff also lived for a decade in Huntington Beach, Calif., where he designed airbrush calendars and postcards that were sold in souvenir shops.

His former landlord, Jerry Smith, recalled Bergendorff frequently paid his rent late. He was being evicted when he declared his illustration business bankrupt in April 1990. Bergendorff claimed $309,700 in debts and $26,650 in assets.

When Bergendorff finally moved out, he destroyed a darkroom he had built in the two-bedroom apartment, Smith said. He left torn pages from pornographic magazines scattered everywhere.

"He was mad because we had to evict him," Smith said. "It was like he wanted to do something symbolic with these magazines, to shock us."