Show of Evil — William Diehl

It begins with a shocking, unsolved murder. In a small town in southern Illinois, the butchered body of Linda Balfour--with a cryptic code printed in blood on the back of her head--forges a gruesome link to the brutal murder of Bishop Rushman, the beloved Chicago clergyman who had been dismembered years before by the angelic-looking altar boy, Aaron Stampler. The same Aaron Stampler whom defense attorney Martin Vail saved from the electric chair...

Now Vail is Chicago's chief prosecutor, facing the nightmare of his life. If Stampler has been locked away in a high-security institution for the past ten years, how could he have killed Linda Balfour? Then another altar boy turns up dead with a similar inscription in blood on the back of his head. If Aaron Stampler isn't committing these killings, who is? Martin Vail's career--maybe even his life--hangs on the answer....