When a party loses in a court of law, it is often allowed to appeal the decision to a higher court. In some instances, parties are entitled to an appeal, as a matter of right. However, sometimes a party is not able to appeal as a matter of right. In these instances, the party may only appeal by filing a writ of certiorari. If a court grants the writ of certiorari, then that court will hear that case.
United States Supreme Court
Certiorari is most commonly associated with the writ that the Supreme Court of the United States issues to review a lower court's judgment. A case cannot, as a matter of right, be appealed to the U.S. Supreme Court. As such, a party seeking to appeal to the Supreme Court from a lower court decision must file a writ of certiorari.
In the Supreme Court, if four Justices agree to review the case, then the Court will hear the case. This is referred to as "granting certiorari," often abbreviated as "cert." If four Justices do not agree to review the case, the Court will not hear the case. This is defined as denying certiorari.
Most of the Justices participate in a "cert pool," meaning their law clerks collectively assign out among themselves the various petitions for certiorari (known commonly as "cert petitions") and prepare memoranda for the Justices summarizing the issues and recommending whether or not the Court should grant certiorari. Critics of this process note the shrinking number of cases the Court has agreed to hear in recent years, theorizing that the "cert pool" tends to increase the number of recommended denials.
Reasons For Granting Or Denying Certiorari
Rule 10 of the Supreme Court Rules lists the criteria for granting certiorari and explains that the decision to grant or deny certiorari is discretionary. A decision to deny certiorari does not necessarily imply that the higher court agrees with the lower court's ruling; instead, it simply means that fewer than four justices determined that the circumstances of the decision of the lower court warrant a review by the Supreme Court. The Court's orders granting or denying certiorari are issued as simple statements of actions taken, without any explanations given for denial. Some have suggested that the Court should indicate its reasons for denial. However, in Maryland v. Baltimore Radio Show, Inc., 338 U.S. 912 (1950), the Court explained that because of practical considerations (such as allowing the Court to carry out its duties), Congress has allowed the control of the Court's business to remain within the Court's discretion.