There is no precision in life. No certainty. Particularly in the realm of policy for communities.
Everyone wants the same ideal: help those who need it, force those who don't to fend for themselves rather than allowing them to leach off of the rest of us; imprison those who are unrepentant and dangerous, those who have caused harm, and free those who have paid for their crimes, are no longer a threat, or who were falsely accused. We don't differ in that.
Instead, what we differ on are the errors we would rather make. Given you can't be sure who really deserves help and who is malingering, would it bother you more to think that someone is taking advantage of your kindness or that you are ignoring someone with real need? Given you can rarely be sure of real guilt, much less future threat, the real question when it comes to crime is which sin you think is worse: the individual who commits a crime free of any consequence or the state that falsely imprisons someone who deserves freedom.
Are you more tolerant of sins by the individual against the group or by the group against the individual? I wonder if that alone most defines someone's politics.