Death of a Gentle Lady by M. C. Beaton

Gentle by name, gentle by nature. Everyone in the sleepy Scottish town of Lochdubh adores elderly Mrs. Gentle--everyone but Hamish Macbeth, that is. Hamish thinks the gentle lady is quite sly and vicious, and the citizens of Lochdubh think he is overly cranky. Perhaps it's time for him to get married, they say. But who has time for marriage when there's a murder to be solved? When Mrs. Gentle dies under mysterious circumstances, the town is shocked and outraged. Chief Detective Inspector Blair suspects members of her family, but Hamish Macbeth thinks there's more to the story, and begins investigating the truth behind this lady's gentle exterior.