Doctor, Lawyer... — Collin Wilcox

Hastings chases a serial killer whose deranged letters hold a city for ransom
The doctor comes through his front door as he always does, a bundle of mail in hand. He's about to walk up the stairs when the bullet passes through his back, puncturing his heart and leaving him dead in his front hall. By the time Lieutenant Frank Hastings arrives, rigor mortis has set in, and the doctor's body rolls easily away from the wall. Pinned beneath him is a note that begins, “Doctor, Lawyer, Merchant, Chief . . .” Pay $100,000, writes “the Masked Man,” or a lawyer will be the next to die.
There are too many lawyers in San Francisco to protect them all, and as Hastings and his team hunt for the Masked Man, the city is whipped into a frenzy of fear. As the killer's demands mount, the homicide department starts to wonder -- after the merchant is killed, will the chief of police be next?