I often wonder about our judicial system and how man can commit another life to prison indefinately....?

I have often entertained the thought about how our judicial is set up. Why do we have governments with regualr men and women who have the capabilites to tell another human being that they will be sentenced to, lets just say, 20 years for stealing. Why are a selected few afforded the right to tell someone elese that their life is not worthy enough for the same freedoms that they enjoy. I pose this question, because in the recent news it show that these politicans are no better morally than the people that they are sentencing to these harsh jail times. Why are these politicians, judges, policemen, and the like able to commit crimes under the same laws that they create for everyone else, but dont have to serve time?