Liar, Liar by James Patterson & Candice Fox

In this episode, our heroine, Detective Harriet Blue is wanted as a rogue cop, going after a serial killer who has murdered indiscriminately, then killed her brother after setting him up to take the fall for several deaths he did not cause, and trying to kill her temporary partner.  He’s after doing the same thing to her and using a psychologist as his gopher to blame or cause her own death.  It’s intense with no let-up throughout the whole book.  It goes from dark to bleak and never comes back.