Why do we need justice and judiciary system ?

Most of the times one explanation prevalent by hinds when questioned why do we suffer in luz of our oven ignorance and prarabha Karma that we carry from our pest lives? But why do more need justice and judicicay then? I mean Someone beat me but because of my Karma from my past lives I somehow deserved the punishment) Am I grossly miSinterpreting theory of karma here? Thanks in advance!