TROY, Ohio — The one-story, brick ranch-style home blends into the working-class neighborhood along Nutmeg Square in this western Ohio city, offering no signs of the terrible secrets it once concealed.

Its former owner will return to court in Dayton on Tuesday to be sentenced for guilty pleas to child rape and related charges in a haunting case that experts call unusual because the perpetrator was an adoptive father and the victims were three boys in his care. The pleas have all but ensured he will spend the rest of his life in prison.