The End of the Pier — Martha Grimes

In a small, sleepy resort town where the lake divides the rich from the just-folks, and where secrets are almost impossible to keep, Maud Chadwick waits tables at the Rainbow Cafe. Her only confidant is the town sheriff, Sam DeGheyn, and what they share in common is obsession: Maud cannot bear watching her twenty-year-old son take his final steps out of her life and into' his own; Sam cannot let go of the unsolved murders of three local women and his intuition that the killer is still out there....