The case of the green-eyed sister

Mason's client wants to get hold of a tape recording that has damaging evidence against her father and a man named Jay Jay Fritch. But Grogan, a blackmailer, wants $20,000 for it! Then Fritch is found DEAD! Grogan has an iron-clad alibi-while Mason and his client have none. Any one of FIVE people could have killed Fritch. Perry must prove that NONE of these five did it-including himself.