The Rottweiler - Ruth Rendell

The first victim had bite marks on her neck so the London papers nicknamed her killer, "the Rottweiler."
He has been stalking the small and diverse London community of Lisson Grove, where Inez Ferry runs an antique shop frequented by a motley collection of eccentric individuals.
When the Rottweiler's trinkets start showing up in the shop, suddenly, everyone Inez knows is a suspect, and the killer feels all too close.
Enthralling and deeply unsettling, The Rottweiler alternates expertly between the mind of a psychopath and the daily affairs of those living in his shadow.
It is a transfixing mystery that only Ruth Rendell could write.