Yiambilis answered the door for the first responders and they found his mother unconscious in a bedroom, police said. Karen Yiambilis, 59, was taken to Aria Health's Torresdale hospital, where she was pronounced dead. Her cause of death was listed as carbon-monoxide poisoning and the manner of death was listed as homicide, Bensalem Sgt. Andrew Aninsman said.
Bucks County District Attorney David Heckler said Yiambilis might have planned to claim another victim that night - himself.
"I think a fair reading of this situation is that he may have intended to do himself in as well," Heckler said. "He ran the generator in, what I gather, is a fairly small apartment, and she was elderly and had some health issues, which may have made her more susceptible."
Heckler said Yiambilis was lying in the same bed as his mother when neighbors first heard the generator running and smelled the fumes. Heckler said Yiambilis may have turned the generator off when questioned by neighbors but later turned it back on, which is when police were called.
"I think they were both inclined, or at least she was and probably he was, to commit suicide," Heckler said.
A motive has not yet been determined.
Yiambilis remains hospitalized. He was arraigned at bedside yesterday and charged with homicide, risking a catastrophe and related offenses.
Just three weeks ago, Yiambilis was arrested for public drunkenness in the middle of a Thursday afternoon when police responded to a Wendy's in Newtown Township and found him sitting in the restaurant fast asleep with a cheeseburger in his hands, according to a Newtown Township police report that was posted on BucksLocalNews.com.
On Twitter: @FarFarrAway