Dave Brandstetter is a terrific protagonist -- he's smart, tough, clever, compassionate, dogged.  He's working through deep grief at losing his partner Rod, and going back to work keeps him focused and moving.  He listens to people well, thinks tangentially as a detective should, and gets inside the head of the person whose death he's investigating for his insurance company.  The whole series is worth working to find -- it's old and mostly out of print.