"He had a bruise of his abdomen that was healing, a bruise under his scalp, a hemorrhage under his head, as well as multiple healed rib fractures," O'Hara said. "He took a tumble at some point."
O'Hara said he could not release further details about the circumstances in which Kinkade was found or the activities leading to his death, given the pending investigation.
His brother Patrick Kinkade did not immediately return a call seeking comment Tuesday but has said the painter battled alcoholism and had relapsed before his death.
Kinkade's commercial successes did not endear him with the art establishment, who criticized him for appearing to appeal to the widest possible audience, his brother told The San Jose Mercury News.
The attacks on his work and the artist's split with his wife two years ago took a toll, and he turned to alcohol over the past four or five years, Patrick Kinkade said.
"As much as he said it didn't bother him, in his heart deep down inside it would sadden him that people would criticize, so hatefully, his work and his vision, when people didn't understand him," said Patrick Kinkade, an associate professor of criminal justice at Texas Christian University.
Associated Press photographer Paul Sakuma in San Jose also contributed to this report.