Secret Hangman

Widowed Inspector Peter Diamond is being pursued by a secret admirer even as he pursues a serial killer.
First, Delia Williams, a waitress with two young daughters, is reported missing by her mother. She is soon found dead in a public park, hung from the crossbar of a swing set. It looks like suicide but the postmortem reveals that she was murdered.
Delia was divorced, living with a new man. Her former husband lives in the vicinity. And she had been chatted up by a customer at the restaurant, a traveling salesman, the night she was killed. Diamond has three suspects to investigate.
Other deaths by hanging follow, with Mrs. Williams's ex-husband among the victims. Now earlier deaths are attributed to this killer. The latest bodies are found prominently positioned in public places around the historic city of Bath. The murderer is no longer shy. What is he trying to say?
Peter Diamond must unravel motive and means before more people are killed by this secret hangman.