In court they would look for a devils mark on the person that is being accused. If they did find a mark then that would mean that the person is guilty of being a witch. Also they would prick the person that is being accused with a needle or pin. If the person felt pain then they aren't a witch if they didn't then they are a witch. They did that because they thought that witches can't feel pain so if the person that was being accused did not scream then they are automatically guilty of being a witch.