Steven Curtis, 58, was arrested Monday at the Oaks of Brecksville in a Cleveland suburb. Roy Curtis, 86, died a few hours later.
Members of the nursing home staff called police to say that the younger Curtis, who appeared to be drunk, had put his hands over his father's mouth. They said he also threw a telephone and assaulted a staffer who tried to stop him, and then attempted to shut himself in his father's room.
Curtis pleaded not guilty at a court appearance. His lawyer, Thomas Shaughnessy, said Roy Curtis was dying of cancer and his son did not want him to suffer.
"It's my understanding that they had ceased all food and water," Shaughnessy said. "He was simply on morphine for the last 72 hours, and this gentleman had actually stayed at the nursing home for all three days. He had actually slept there and was with his father."
Curtis was freed on $50,000 bail.