Stunned silence..
Where the heck did you learn all that??
History and imagination.
Oppressed people have always stolen weapons from their oppressors in order to fight back.
In WWII the French did it.
The Filipinos REALLY did it.
The Dutch, Greeks and others did it.
Just think about where the guns are and plan to take them. Being on Staten Island an armored car would be easier to get than a D-9. Or a fire truck, dump truck or whatever is handy. Crash the gate with a band of like minded people and loot the goodies.
As far as trained personnel there are more around you than you think. Look at the people and cars around you. Former military tend to quietly advertise themselves. Caps, jackets and lapel pins often show what branch of service they were in.
Vanity license plates often show branch of service as well as honors and medals received.
Window stickers on cars are also a good tell.
You can actually find older military manuals online if you search.
I did some quiet listening and have found that in a three mile radius of my home we have 1 current state trooper, 2 retired troopers, two retired pilots, several former army, a couple of former marines and a truckload of hunters.