1ST To Die by James Patterson. 
Four crime-solving friends face off against a killer in San Francisco in the Women's Murder Club novel that launched James Patterson's thrilling series. Each one holds a piece of the puzzle: Lindsay Boxer is a homicide inspector in the San Francisco Police Department, Claire Washburn is a medical examiner, Jill Bernhardt is an assistant D.A., and Cindy Thomas just started working the crime desk of the San Francisco Chronicle.    But the usual procedures aren't bringing them any closer to stopping the killings.