The Hurricane Killer. Shannon Flynn Mysteries, #1

Shannon Flynn, best selling author and hard hitting, hard drinking ex-NYPD private detective, desperately needs new material to make the deadline for her next novel, stalled out by writer's block. She takes on the investigation of a cold case involving a serial killer who has left a trail of mayhem and gore all over New York State for twenty years. The investigation leads her in directions she cannot even begin to comprehend; embezzlement and fraud at her publisher's, mob involvement, corrupt bankers, the murder of one of the publishing house's owners, and the death of a young girl for which Shannon feels personally responsible.
The killer's identity, when finally revealed to her, is  incomprehensible. It changes her view of humanity, her view of her own industry, and changes her life in a way that she cannot begin to understand.