Every Dead Thing

Description for EVERY DEAD THING by John Connolly:

Step into the tortured mind and gritty world of former NYPD detective Charlie "Bird" Parker, who is tormented by the brutal, unsolved murders of his wife and young daughter. Driven by visions of the dead, Parker tracks a serial killer from New York City to the American South, and finds his buried instincts - for love, survival, and, ultimately, for killing - awakening as her confronts a monster beyond imagining....

This is #1 in Charlie Parker Series.