3rd Degree (#3) by James Patterson and Andrew Cross

One of James Patterson’s Best-loved heroines is about to die.

Detective Lindsay Boxer is jogging along a beautiful San  Francisco street when a fiery explosion rips through the neighborhood. A town house owned by an Internet millionaire is immediately engulfed in flames, and when Lindsay plunges inside to search for survivors, she fines three people dad. An infant who lived in the house cannot be found-and a mysterious message at the scene leaves Lindsay and the San Francisco Police Department completely baffled.

Then a prominent businessman is found murdered under bizarre circumstances, with another mysterious message left behind by the likker. Lindsay asks her friends Claire Washburn of the medical examiner’s office, Assistant D.A  Jill Bernhardt, and Chronicle reporter Cindy Thomas to help her figure out who is committing these murders- and why they are intent on killing someone every three days.

WHICH ONE WILL IT BE?