While that is true, we also convict innocent people by accident or malice. We need to design a court / legal / penal system that is fair toward the innocent, not vindictive toward the guilty.

If a mugger gets out after a year and commits more violent crime, sign them up for five years. If they get out and commit more crime, sign them up for ten years. Once they get out of their 20s, most males calm down. If not, put them away for life.