Criminal Law: Crimes against property – Miscarriage of justice, + Compounding a felony

A miscarriage of justice, also known as a failure of justice, occurs when a person is convicted and punished for a crime that they did not commit. It is seldom used as a legal defense in criminal and deportation proceedings. The term also applies to errors in the other direction—"errors of impunity", or to any clearly unjust outcome in any civil case. Every "miscarriage of justice" in turn is a "manifest injustice." Most criminal justice systems have some means to overturn or quash a wrongful conviction, but this is often difficult to achieve. In some instances a wrongful conviction is not overturned for several decades, or until after the innocent person has been executed, released from custody, or has died.

Compounding a felony was an offence under the common law of England and was classified as a misdemeanor. It consisted of a prosecutor or victim of an offence accepting anything of value under an agreement not to prosecute, or to hamper the prosecution of, a felony. To "compound", in this context, means to come to a settlement or agreement. It is not compounding for the victim to accept an offer to return stolen property, or to make restitution, as long as there is no agreement not to prosecute.

Under the common law, compounding a felony was punishable as a misdemeanor. Many states have enacted statutes that punish the offence as a felony. Compounding a misdemeanor is not a crime. However, an agreement not to prosecute a misdemeanor is unenforceable as being contrary to public policy.

Compounding has been abolished in England and Wales, in Northern Ireland, in the Republic of Ireland, and in New South Wales. In each of these cases, it has been replaced by a statutory offence.