It is possible the actors were forewarned of the secret purpose of this drill, but even that is not so relevant, they are anyway constantly performing such activities in drills etc. That is why we are seeing the same people over and over again. The likelihood of actual physical damage to anyone is minimal, all the legal institutions are complicit in the hoax angle, Police, FBI, White House, Coroners, they surely could not be complicit in actual real killings, injuries and abuses of the law. However for the seeming purpose of disarming Americans or similar they can play along with a hoax.
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