«Fault Lines» by Anna Salter

Drawing on her real-life expertise as a forensic psychologist to create "a crackling, suspenseful mystery" (Andrew Vachss), Anna Salter debuted an unforgettable heroine, Dr. Michael Stone, in Shiny Water. Now, in a thrilling new novel, Michael Stone deciphers the twisted logic of a sexual predator – and crosses into deadly territory.
A devastatingly violent attack has left one of Michael Stone's clients paralyzed by fear; her only security is the attack dog who never leaves her side. Michael has her own self-protection: even when she steps into the hot tub on the deck of her sparse A-frame house in the Vermont woods, she takes her gun. Michael has learned the hard way that her profession invites danger: she's a forensic psychologist – an expert in analyzing and, in a perfect world, outsmarting the criminal mind. But some deviants will never be understood or rehabilitated – like the purely evil perpetrator who has crossed Michael's path before.
Alex B. Willy is a sadistic child molester, a man of monstrous deeds and chilling obsessions. Attempting to profile the psychological makeup of a molester, Michael glimpsed the darkness within through her interviews with the incarcerated Willy; flattered by her attention, he had disclosed the modus operandi of a pedophile, and even boasted about his crimes on audiotape.
Now, his thirty-year sentence suddenly cut short, Alex Willy has been granted a retrial and is sprung from prison. And the one person who threatens his freedom, who knows the depths of his sickness and his seamless lies, is Michael Stone.
Her friends want to hide her, while Michael – gutsy, aggressive, and fiercely protective of her privacy – feels safety lies in evading her stalker on her own terms. With horrifying brilliance, Willy has devised an even better way to get to Michael. Invading her professional world, Willy taunts her with malevolent e-mail messages and an intimate knowledge of her clients. Moving in her shadow but always two steps ahead, Alex B. Willy soon targets Michael's guarded personal life, delving along the fault lines of her psyche – and setting her up for a chilling coup de grace.
As authentic as a case file, and as relentless as a nightmare, Fault Lines firmly places Anna Salter alongside Patricia Cornwell and Jonathan Kellerman in a master class of top-notch psychological suspense writers.