The problem in the judiciary system in both the town and the borders is that there is hardly enough proof to find anyone’s innocence. The convict can be anyone who is pointed out to be. At times there is no one to proof properly what happened. Without proper witness an innocent person can be turned into a guilty party.
The judges rely on the words of the people present instead of searching for proper explanations in the situation. Such thing was happening to Miles. He was not the person present around the people. They put him under arrest for the murder of the soldiers in the ground.