Actual innocence is a special standard of review in legal cases to prove that a charged defendant did not commit the crimes that they were accused of, which is often applied by appellate courts to prevent a miscarriage of justice.
[1][2] In its most literal sense, "actual innocence"—more properly understood as a claim that the prosecution has failed to prove factual guilt beyond a reasonable doubt—is a very commonly raised defense to a crime.
Arguably, even affirmative defenses such as "self-defense", insanity, or "mistake of fact" qualify as "actual innocence" claims because while in those cases the accused admits to both their identity as the actor and to the existence of the act ("actus reus"), they are claiming that the State cannot prove that they had the requisite mental state ("mens rea") to constitute a crime.
The Tarlton Law Library at the University of Texas at Austin maintains an "Actual Innocence awareness database" containing "resources pertaining to wrongful convictions, selected from the popular media (such as newspaper articles and segments which aired on television news magazines), journal articles, books, reports, legislation and websites".
At trial, the defendant enjoys a due process right to the presumption of innocence, and the State is obligated to prove the guilt of the accused beyond a reasonable doubt.
The second method of attacking the validity of a conviction is known as "collateral" review, and can take many forms, including state and federal petitions for writs of habeas corpus, petitions for writs of error coram nobis, and—increasingly—a newly developed form of collateral relief which allows petitioners to raise claims of actual innocence, whether through DNA testing or through some other method.
By contrast, defendants such as Jeffrey Dahmer, Susan Smith, and Lorena Bobbitt conceded that they committed the criminal act, but raised defenses such as insanity or diminished capacity.
While some argue that this is unjust for the convicted, it is rationalized that continued specter of "actual innocence" after the conclusion of a trial would make the adjudication process moot, which may lead to rule of law problems.
The Supreme Court has ruled that convicted persons do not have a constitutional due process right to bring DNA-based post-conviction "actual innocence" claims.
Following reports of a sizable number of DNA-based exonerations, some states also have adopted broader "actual innocence" statutes allowing post-conviction challenges on the basis of newly discovered evidence in general.
The United Kingdom, like all 47 Member States of the Council of Europe, is a signatory to the European Convention of Human Rights,[5] and is prohibited by Article 3 from using the death penalty so there is no longer the fear that an innocent man may be executed.
The case of prisoner Troy Davis, executed 21 September 2011, illustrates the difficulties that a person has, once convicted, to prove his "actual innocence" in the U.S.