Humans really do have agency. Not all criminal behavior can be chalked up to bad policy or bad environment.
If cause and effect exists in human beings as they do for literally everything else, than claiming 'agency' as an excuse to do nothing is basically moral bankruptcy.
Our science is not perfect, nor is our policies, and people will fall through the cracks, but we should keep striving and trying nonetheless.
Some causal things society would likely be unwilling to give up; and so some portion of society being sacrificed to prisons is what we're willing to pay for it.
If cause and effect exists in human beings as they do for literally everything else, than claiming 'agency' as an excuse to do nothing is basically moral bankruptcy.
Our science is not perfect, nor is our policies, and people will fall through the cracks, but we should keep striving and trying nonetheless.