Miscarriage of justice in the context of "Perjury"

A pardon is a government decision to allow a person to be relieved of some or all of the legal consequences resulting from a criminal conviction. A pardon may be granted before or after conviction for the crime, depending on the laws of the jurisdiction.

Pardons can be viewed as a tool to overcome miscarriage of justice, allowing a grant of freedom to someone who is believed to be wrongly convicted or subjected to an excessive penalty. The second-best theory of pardons views pardons as second-best to fair justice. Pardons can be granted in many countries when individuals are deemed to have demonstrated that they have "paid their debt to society", or are otherwise considered to be deserving of them. In some jurisdictions of some nations, accepting a pardon may implicitly constitute an admission of guilt; the offer is refused in some cases. Cases of wrongful conviction are in recent times more often dealt with by appeal rather than by pardon; however, a pardon is sometimes offered when innocence is undisputed in order to avoid the costs that are associated with a retrial. Clemency plays a critical role when capital punishment exists in a jurisdiction.

Wrongful execution is a miscarriage of justice occurring when an innocent person is put to death by capital punishment. Opponents of capital punishment often cite cases of wrongful execution as arguments, while proponents argue that innocence concerns the credibility of the justice system as a whole and does not solely undermine the use of the death penalty.

A variety of individuals are claimed to have been innocent victims of the death penalty. Newly available DNA evidence has allowed the exoneration and release of more than 20 death-row inmates since 1992 in the United States, but DNA evidence is available in only a fraction of capital cases. At least 190 people who were sentenced to death in the United States have been exonerated and released since 1973, with official misconduct and perjury/false accusation the leading causes of their wrongful convictions. The Death Penalty Information Center (U.S.) has published a partial listing of wrongful executions that, as of the end of 2020, identified 20 death-row prisoners who were "executed but possibly innocent".

Contaminated evidence is any foreign material that is introduced to a crime scene after the crime is committed. Contaminated evidence can be brought in by witnesses, suspects, victims, emergency responders, fire fighters, police officers and investigators.

Juries expect to see forensic evidence before they render a verdict based on that evidence. Because of this, attorneys on both sides try to discredit forensic evidence that does not support their clients' interests. This requires crime scene investigators be especially careful to guard against contamination in the forensic samples. A miscarriage of justice can occur when these procedures are not carried out carefully and accurately.