Shadow Man by Alan Drew

Ben is a L.A. detective with a teenage daughter, an ex-wife who wants a new life and a serial killer on the loose. The Shadow Man lives in the hills along the sea preying on the unsuspecting women and girls who live in the beautiful homes near the water. Finding him is driving Ben crazy. He is also struggling with a secret that could save others from what he went through. Police drama led by a not so tough nice guy cop turned cowboy in the California hills.