"bad guys will always be bad"
"If criminals can change what is the point of having police"
Holy shit that's a lot of bullshit, I get that this story is operating on a slightly heightened sense of reality where criminals are supervillains or something, but that is an objectively insane take on the justice system and one that leads to honest-to-god atrocities in the real world.
Even if the story is saying she is wrong and that reform rather than retribution is desirable, the fact that "once a criminal, always a criminal" is even being proposed makes one of the protagonists feel like an alt-right psychopath.