Books in the Pete Stone, Private Investigator series

A young woman is stabbed to death in Wichita. Within hours police nab a suspect and put him behind bars. The case is open and shut, until a university professor calls on Pete Stone, Private Investigator, to prove that the suspect is innocent. He hires Stone to find the real killer. Stone harbors doubts about the professor and his motives; the professor is keeping secrets of his own. Another murder, too similar to the first killing, leaves puzzling clues that point to the professor. Is he a serial killer, a mere pawn in a cruel game, or the next victim? Stone must find answers before another innocent person is slain.