LAS VEGAS — 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 between 1990 and 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."