While I'm inclined to think some of these shootings are false flags, this one didn't play out like one. The incident started in a cemetery and proceeded a half mile away to a supermarket as the perps tried to flee. I work in Jersey City and was following this on the police radio scanner. Besides the one cop who died and the two perps, there were three civilians who were found dead in the supermarket. By today's standards, four victims and the two perps dead is hardly a "mass" shooting.
So I heard that this was an undercover drug buy that went south. Is that the info from your location?