I find it ironic that you talk about distrust but then use ACAB, which I assume means "all cops are bad" (cursory googling).
The effects only get more pronounced in a society where literally every lunatic could have a gun and could therefore murder you at the drop of a hat. Trusting a strange situation will mean your death, eventually. It's inevitable.
This is therefore not a matter of distrust, because you don't need faith or trust to know certain things about the transformative effect this would have on people. They live under mortal threat every second they're outside in uniform. They're going to be monstrous.
They're ultimately good guys (well, as good as any random guy is, not worse not better) but their experience of the society turns them into distrustful, clanic semi-sociopaths. The fear of other people reactions is ingrained.
The one that marked me is that they were afraid of local teens chatting up with our teens and learning they were police children, and passed that fear to all kids by saying extremely weird and violent shit they probably believed, but were ultimately lies. They wanted the children, most of them orphans, to avoid talking to regular kids outside of the camp, and lie if they did.
Not bad guys inherently, but clearly fucked up by their job.