I kinda like the original concept of an outlaw, as in, someone who lost the protection of the law. It really kind of seems to me like actual justice in many cases.
Think about it. If for example, you murder someone, why the heck should anyone else be punished for murdering you right back? I mean, it's not like you believe people have the right to live.... just saying 

 @d0e09e5d eye for an eye is as old as time itself 

 @d0e09e5d 

It is a good point. Once you violate the social compact, there is no reason to protect you.

But trial by jury is a useful innovation.