Showing Day of Wrath by Jonathan Valin

Sheltered but precocious teenager Robbie Segal has run away from her home, a small brick house on an unexceptional street. Her desperate mother has asked PI Harry Stoner to find her. What begins as an ordinary missing-persons case - a case that should be settled without any violence at all - suddenly changes in an impossibly terrifying way. Now Harry is on the trail of a shockingly brutal act of murder, because it might lead him to a runaway girl, because it had become part of the job, because something deep and indelible inside him simply has to.