The union for police officers who work San Francisco home games says its members may boycott policing the stadium if the 49ers don't discipline Colin Kaepernick for refusing to stand during the national anthem and for his statements about law enforcement. A letter from the Santa Clara Police Officers Association sent to the 49ers was obtained Friday by KNTV-TV, the NBC affiliate in San Jose. It says that Kaepernick's protest has ''threatened our harmonious working relationship'' with the 49ers. More...