When a teenager is shot at the beach, a journalist from The Miami Journal is sent to cover the story. He's called by the murderer and told there'll be four more.
 
It reminds me of a poorly done Zodiac (2007).
 
FUN FACT:  Originally the source material was in a yet unpublished novel form, written by John Katzenbach in 1982. The manuscript then landed on Producer David Foster's desk. Foster optioned it as a film, and the property then got published as a novel named "In The Heat of Summer".