The Devil Drives — Peter M. Wright

Horace the Falcon is a serial killer straight out of the heart of darkness. He stalks middle-aged men, leaving them emasculated and prepared to cross the river to the dead side. Barton Keene, a private investigator recently separated from the San Francisco Police Department, aids the police in the pursuit of the Falcon. Keene shares his skill with a local police detective and a valley wine grower as they probe the darkest corners of this subhuman psycho. John McGarry, a retired F.B.I. criminal profiler, is hired by the police to provide his profiling know-how. However, he is not welcome. Manny Fiorello, a retired Mafia hit man, arrives in the valley to connect with other retirees. Fiorello becomes very instrumental in the hunt for the Falcon and the final verdict. Barton Keene lives in an old wooden house he calls Casa Viejo. His housemate is an old tomcat called Crazy Christian.