Trial By Combat
The accused of a crime may ask for a trial by combat. This combat can be fought by the accused herself, or a Champion she secures. For petty crimes, these can be considered regular honor duels, but for serious, capital crimes, the rules are different.
In these serious cases, the duel is to first yield/incapacitation. If the accused yields, it is a death sentence, for her guilt is proven. If her Champion yields after a minor wound, that Champion might be ruled dishonorable by the Champions guild and prohibited from taking part in future, sanctioned duels.
As with any duel, failing to honor a yield is treated as murder, even if the murdered party is accused of a capital crime and their life is on the line. Champions are not executioners, even in trial by combat.