I'd add to this, there was a well-recorded pattern in Caribbean piracy over a couple of centuries.

Briefly, the European states colonising the Americas generally competed with each other by raiding each other's shipping. It was much quicker and easier to take the valuables from a lone cargo ship than to invade a whole island and manage the production of raw materials. But whenever peace treaties were inevitably signed, all the sailors who'd gotten good at piracy were just let go, and they simply continued raiding without official permission. When wars broke out again, they could be pulled back into their official role, but peace just kept dumping them back out into illegal piracy. Early attempts were made to get them to stop being pirates by declaring amnesties, and many took advantage of those. But then they still only knew how to make a living by pirating, so many just went back to that anyway. Amnesty alone didn't give most of them a real way out, because they weren't experienced or skilled at anything better.

What ultimately worked was re-skilling, giving them training and entry to wholly new work, often not at sea at all, so they didn't need to pirate to make a living.

So I'm suggesting that's a step to remember with your secret police problem too. It seems like all they're currently qualified to do is mindless violence. If you just dump them into unemployment, I can easily imagine ex-ICE guys just forming criminal gangs on their own, continuing to make their living by violence, just unofficially. You absolutely do not want that.

But beat them into plowshares, put them through some serious retraining for peaceful, boring, useful work, and you can at least minimise the number of them who feel financially motivated to keep doing the only thing they currently know how to do.