defendant who seeks relief for some perceived error in his criminal trial. There are a number of such post-trial actions and proceedings, their differences being potentially confusing, thus bearing some explanation. Some of the most common are an appeal to which the defendant has as a right, a writ of certiorari, a writ of coram nobis and a writ of habeas corpus. An appeal to which the defendant has a right cannot be abridged by the court which is, by designation of its jurisdiction, obligated to hear the appeal. In such an appeal, the appellant feels that some error has been made in his trial, necessitating an appeal. A matter of importance is the basis on which such an appeal might be filed: generally appeals as a matter of right may only address issues which were originally raised in trial (as evidenced by documentation in the official record). Any issue not raised in the original trial may not be considered on appeal and will be considered waived via estoppel. A convenient test for whether a petition is likely to succeed on the grounds of error is confirming that a mistake was indeed made an objection to that mistake was presented by counsel and that mistake negatively affected the defendant's trial. A writ of certiorari, otherwise known simply as cert, is an order by a higher court directing a lower court to send record of a case for review, and is the next logical step in post-trial procedure. While states may have similar processes, a writ of cert is usually only issued, in the United States, by the Supreme Court, although some states retain this procedure. Unlike the aforementioned appeal, a writ of cert is not a matter of right. A writ of cert will have to be petitioned for, the higher court issuing such writs on limited bases according to constraints such as time. In another sense, a writ of cert is like an appeal in its constraints; it too may only seek relief on grounds raised in the original trial. A petition for a writ of error coram nobis or error coram vobis challenges a final judgment in a criminal proceeding. Use of this type of petition varies from jurisdiction to jurisdiction, but is usually limited to situations where it was not possible to raise this issue earlier on direct appeal. These petitions focus on issues outside the original