This was how Daggerfall's system worked:
Pleading guilty--->judge goes a little easier on your prison sentence
Pleading not guilty---> chose to either "Lie" or "Debate" about your crime to prove innocence
Failure to Prove innocence with Lie or Debate---> Maximum jail sentence
Success in proving innocence---> you get no sentence. you are free and your name is cleared.
^i don't think a system this simple should be in Skyrim, but i'm just saying this was pretty cool for a game made at that time.
In addition to this, I want a death sentence if your crimes are bad enough... Imagine being publicly beheaded or hanged in first person.