CSG is a part of the PNP, but is an administrative arm, purely dealing with firearm certificates, explosive permits and the supervision of private security agencies. Each city is also legally empowered to maintain it's own civilian security (vigilantes), which is most probably the group described as CSG. I suspect the civilian security was carrying a gun and was confronted by the PNP and a firefight broke out and that's where the story goes haywire. Whom shot the five dead. Perhaps when this incident is properly investigated, then the truth will come out ?.