Showing Winter at the Door by Sarah Graves

Lizzie Snow was first introduced in the final book of Graves's previous series, BAT IN THE BELFRY, in which she helped Jake Tiptree find who killed a girl and left her body in a church steeple. Now Lizzie has taken over as Eastport's police chief, and is quickly finding the job - and her life - more complicated than she expected.

Then she learns that someone seems to be killing retired detectives in the state... and that she has been followed from Boston to Maine by a mysterious stalker whose chilling intentions will drive her to the edge.