Clarkstown police said in a statement Wednesday that there was no sign of forced entry at the Valley Cottage home of Peggy Nadell.
They said there is "a strong possibility" she knew her assailant. They believe there is no danger to others in the hamlet about 25 miles north of New York City.
The police said Nadell was found dead Saturday morning by her daughter.
Nadell was a longtime Rockland County Democratic committeewoman and was outspoken on environmental and women's rights issues.
Her funeral was held Wednesday.
Anyone with information is asked to call 845-639-5800.