> That violent people should be removed from society to prevent them from injuring other people?
No, I made it clear that I believe the efficacy of a prison system should be measured by total population crime rate and recidivism rates. The US prison system fails to achieve the goal you're implying it does. It has a very high recidivism and reconviction rate. In a sense, my point is more that "we've tried it your way and it's not working."
The goal should be to, as you say, "stop people from injuring other people" in the future. You can't un-injure someone in the past, and the constitution provides for proportional punishments in the 8th amendment if I'm not mistaken, so people will end up out of prison at some point. The question on my mind is how to make sure that when they do, they don't injure more people.
Recidivism rates are available for your review: [1]. My point is rather that the plan you're advocating for isn't achieving the result that you're telling me it is.
> Being in a constant state of understanding is not how you govern a country if you want it to be peaceful and cleaned up.
Being data-driven is how you achieve goals, and the data says this is the wrong approach.
The duty of the state shouldn't be to exact revenge (which by the way, studies show, after a threshold incremental punishment does nothing) but rather to give folks the tools to escape their environments. That means showing them how to live in the real world.
At the end of the day the state should measure the efficacy of a prison system against recidivism and total population crime rate. The individual cases shouldn't really factor in.