They aren't "training" them. Certainly not as well as actual soldiers. But they are arming them with more and more military gear. If you were a high-school bully who never grew up or a racist who wanted to harass and maybe even kill a black person, what job would you get?
They hire ex-cop contractor buddies and give them gobs of municipal money to do a 'training' session where they brainwash the entire force into thinking that they're at war with an insurgency as dangerous to them as alqueda was to the military that so many of them came from.
This is one of the reasons they're so trigger happy. Right from academy they're taught this, and any recruits who question it get dropped. One of the more famous programs is literally called 'Kill-ology'.