If a person pleads guilty to a crime he or she did not commit and is sentenced for that crime, can he or she later change their mind and have the case retried?

Usually, the answer is no. Once you have been sentenced for a crime, the issue as to guilt is considered resolved. However, there are "post- conviction remedies" available in certain situations to persons who have been convicted and sentenced for crimes, both on the state and federal level. The laws vary from jurisdiction to jurisdiction, but generally, they permit the Court to set aside a guilty plea if the plea or sentence was imposed in violation of a constitutional right; if the sentence imposed was illegal (as opposed to merely harsh, such as if it exceeded the maximum allowed by law for the crime); if the law under which they were convicted is unconstitutional; if the court didn''t have proper jurisdiction over the person or the offense; or if new evidence of material facts have come to light since the conviction, which could not have been learned of at the time of the plea and sentence, and as a result of these new facts, the conviction and sentence should be set aside in the interest of justice. There are varying but strict time limits for requesting such post-conviction relief, both at the state and federal level. If you think you fall into one of the listed categories, contact a lawyer in your state to advise you specifically of any remedies available to you and the applicable time limit for requesting relief.