The family of the L.A. Dodgers fan stabbed to death after a ballgame in San Francisco is urging witnesses to come forward.  Robert Preece made a plea yesterday in front of AT&T Park after prosecutors said they lacked evidence to charge a suspect in the killing of his son, Jonathan Denver.

Preece believes someone videotaped the confrontation that left his son dead.  The 24-year-old Fort Bragg resident was killed in a fight after Wednesday night’s Giants/Dodgers game a few blocks from the ballpark.  Police say it stemmed from an intense baseball rivalry. 21-year-old Michael Montgomery of Lodi, who was suspected in the stabbing, was released from jail over the weekend.