Justice is the official name for the law that grants immunity to Red Cards in Final Fantasy Tactics Advance. Justice is only allowed to be issued by Judgemaster Cid, however, as seen in the beginning of the Corrupt Judges missions, a Judge also issued Justice illegally.
Justice is not available to Marche Radiuju or any member in his clan. Before the first Corrupt Judges mission Cleanup Time begins, Marche is just seconds away from earning Justice from one of the corrupt judges before Judgemaster Cid makes his appearance.
Justice is indicated by a special medal on the characters stat box during an engagement which is known as a "Hero Medal". Justice is commonly given to boss figures in the game such as Babus Swain in mission #009 Emerald Keep. Whenever encountering a character with a "Hero Medal", they do not worry about the current laws in battle as they will never be sent to jail. Because of this, they can earn an infinite amount of Yellow Cards in battle.
Along with the immunity to Red Cards, immunities to some status ailments such as Instant KO and Petrify are granted as well. Because a handful of missions with boss characters is simply a "Defeat The Boss" challenge, status ailments such as those are automatically prevented to prevent a cheap win.