Actual innocence is the most wiely used - yet often the least studied - defense to crime. Most law school criminal law courses focus on defenses that apply where the accused in fact committed a criminal act, but presents an excuse that eliminates their liability for that act. In such cases, the defendant may be acquitted despite the concession that the defendant committed a criminal act. In the vast majority of cases, however, the defense put forth for crime is that the evidence supports the claim that the defendant committed no criminal act at all.