The First Rule – Robert Crais

When Frank Meyer and his family are executed in their home, the police begin investigating the secret life they’re sure Meyer had. Joe Pike’s on a hunt of his own: to clear his friend’s name, and to punish the people who murdered him. What starts out as a simple trail gets twisted fast by old grudges, double crosses, blood vengeance, and a crime so terrible even Pike and his partner Elvis Cole have no way to measure it.