Clemency may be a pardon, shortening of a prison sentence, commutation of a sentence, or a reprieve. Clemency may be granted by each state’s governor and the President of the United States, and may be based upon mercy or other considerations that put a prisoner's guilt in doubt.
A pardon is defined in criminal law as an official act of forgiving a crime. A pardon may be granted under the executive powers of a governor or the President. By granting a convicted person a pardon, the conviction is eradicated from the records, the person is freed from further punishments and penalties, and may not be retried for the same offense.
A pardon may be granted to persons for such reasons as advanced age, acts proving rehabilitation, unfairness of trial proceedings, doubts about guilt of the convicted person, or terminal illness. A pardon does not indicate that the person pardoned is not guilty, but that they are forgiven and no longer deserving of punishment. While laws vary by state, a pardon request usually needs to be accompanied by a lengthy period of exemplary behavior and a reference check. Generally, the more serious the crime, the longer the time requirement for excellent behavior.