Suspect / Michael Robotham.

Enhanced descriptions from Syndetics:

The hunter becomes the hunted when an expert consultant in a baffling murder case becomes the prime suspect in Michael Robotham's stunning debut thriller.

At forty-two, psychiatrist Joe O'Loughlin seems to have it all: a thriving practice, a beautiful wife, an adoring daughter. But Joe's snug, happy world is crumbling. Recently diagnosed with Parkinson's disease, he's dreading the inevitable and all too palpable deterioration of his body and mind. Then, when the police ask for his help in solving the brutal murder of a woman they assume is a prostitute, he's horrified to recognize the victim as a nurse he once worked with, and with whom he had a bit of a past. As Joe begins to suspect that one of his patients may be responsible, the police zero in on him.

Michael Robotham possesses the rare ability to create fully believable characters, fashion terrific dialogue, and generate nonstop suspense. Suspect is a powerhouse first novel, intricately crafted and chillingly authentic.