Neil McMahon 
Twice Dying [EPUB ebook] 

Outside San Francisco, a sting of NGI’s–violent sociopaths found not guilty by reason of insanity–have been sent back into society, and, one by one, mysteriously disappeared….Beautiful psychologist Alison Chapley wants to know why and sets off on a search for answers that lures her and her former lover, medical examiner Carroll Monks, into a menacing and increasingly macabre dance with a brilliant psychopath known only as Naia….Naia’s perverse and carefully chosen clues–plaster masks, a snuff videotape, a deadly cobra–draw Alison into a psychological seduction she’s powerless to resist. Running out of time, Monks’s only chance to save Alison is to outwit this twisted mastermind in a deranged and deadly game of cat-and-mouse.