Who Killed Frank?

What would you do if someone murdered your best friend and mentor?

Private investigator Harry Starke owes his career to Frank Callahan, the tough-as-nails detective who trained him as a young cop. But when Frank is found brutally murdered in his own home, Harry can't let it go.

The crime scene reveals a chilling connection: photos from the unsolved Riverside Strangler case-ten women killed along the Tennessee River a decade ago. Frank had spent his retirement obsessed with the case, convince...