Nigeria operates a federal political structure under the Constitution of the Federal Republic of Nigeria, 1999. The Federation consists of 36 (thirty six) States and a Federal Capital Territory. This constitution vests the legislative, executive and judicial powers of the Federal Republic of Nigeria in the National Assembly, the Executive and the courts established there under respectively. The powers of the States are vested in similar organs, except that the legislative organ of the States is known as the House of Assembly.
The Attorney General of the Federation and Minister of Justice is the Chief Law Officer of the Federation. He is the head of the Federal Ministry of Justice and institutes, undertakes, takes over, continues or discontinues criminal proceedings before courts of law in Nigeria in respect of offences created under any Act of the National Assembly. Likewise, the Attorneys General of the States have similar powers in respect of Laws enacted by the Houses of Assembly of the States.
The development of the Nigerian legal system has been greatly influenced by its colonial past as a part of the British Commonwealth . The common law of England , the doctrines of equity as well as statutes of general application in force in England as at 1 st January 1900 form an integral part of our laws in addition to certain English statutes that have been received into our laws by local legislation. Other sources of Nigerian law include local legislation (State and Federal), Nigerian case law as well as customary law. The principles of judicial precedent and hierarchy of courts is also a fundamental part of our legal system with the Supreme Court of Nigeria at the apex of the court system.
Nigeria operates the adversarial system of court proceedings similar to what obtains in other common law countries. However, the jury system is not used in the system of administration of justice, as the presiding judge is both a judge of the law and fact.
The 1999 Constitution makes provisions for the establishment and constitution of the following courts:
The Supreme Court of Nigeria
This is the apex court in the hierarchy of courts in Nigeria and is situated in the Federal Capital Territory , Abuja . The Chief Justice of the Federation heads the Judiciary of Nigeria and presides over the Court. The court has limited but exclusive original jurisdiction in any dispute between the Federation and a State or between States if and in so far as that dispute involves any question (whether of law or fact) on which the existence of a legal right depends. Its appellate jurisdiction is to determine appeals from the Court of Appeal and this is also to the exclusion of any other court. The court consists of the Chief Justice of Nigeria and such number of Justices not exceeding twenty one as may be prescribed by the National Assembly. Ordinarily, the Court is duly constituted if it consists of not less than five Justices of the Court, except where it is exercising its original jurisdiction or a matter involves a question as to the interpretation or application of the constitution or whether any provision relating to the Fundamental Rights provisions of the Constitution has been, is being or is likely to be contravened. In this regard, the Court is duly constituted if it consists of seven Justices of the Court.
The decision of the Supreme Court on any matter is final and is not subject to an appeal to any other body or person. This is however without prejudice to the power of the President or Governor of a State’s exercise of Prerogative of Mercy in appropriate cases. The decisions of the Court are binding on all other courts in Nigeria.
The Court of Appeal
This is next in the hierarchy of courts in Nigeria and its decisions are binding on all other lower courts. It is composed of the President of the Court of Appeal and other Justices of the Court of Appeal not being less than forty-nine. The court has original and exclusive jurisdiction over questions as to whether a person has been validly elected to the Office of President or Vice President of the Federation or whether the term of office of such person has ceased or whether the office has become vacant. It also has appellate jurisdiction to hear appeals from decisions of the High Courts of the States and the Federal Capital Territory, Federal High Court, the Sharia Courts of Appeal of the States or of the Federal Capital Territory, Customary Courts of Appeal of the States or of the Federal Capital Territory as well as from decisions of a court martial or other tribunals as specified by an Act of the National Assembly. The court is duly constituted by not less than three Justices for the purpose of exercising any of its stated jurisdiction. For administrative convenience, the court is divided into Judicial Divisions which sit in various parts of the country namely, Abuja, Lagos, Enugu, Kaduna, Ibadan, Benin, Jos, Calabar, Ilorin and Port Harcourt.
The Federal High Court
There is a Federal High Court for the country, comprising of a Chief Judge and such number of Judges as the National Assembly may prescribe. The court has limited but exclusive jurisdiction in civil and criminal causes or matters as set out in the Constitution. It however has no appellate jurisdiction. In exercising its jurisdiction, the Court is duly constituted by one Judge of the Court. Like the Court of Appeal, the Federal High Court is divided into Judicial Divisions for administrative convenience but has a wider geographical spread as these Divisions are currently situated in over seventeen states of the Federation with plans to establish a Division of the Court in all the States of the Federation.
The High Court
There is a High Court in each State of the Federation and the Federal Capital Territory . Each Court is made up of a Chief Judge and such other number of judges as the State House of Assembly or the National Assembly (in the case of the High Court of the Federal Capital Territory ) may prescribe. The High Courts of the various States have general original jurisdiction over civil and criminal matters except matters in respect of which any other court has been vested with exclusive jurisdiction, making them the courts with the widest jurisdiction under the Constitution. The court duly constitutes by one judge. Each High Court is divided into Judicial Divisions for administrative convenience.
The Sharia Court of Appeal
There is a Sharia Court of Appeal for the Federal Capital Territory and any State that requires it. This Court has appellate and supervisory jurisdiction in civil proceedings involving questions of Islamic personal law, which the Court is competent to decide in accordance with the Constitution. The Court comprises of a Grand Khadi and other Khadis as the National Assembly or the State Houses of Assembly (as the case may be) may prescribe.
The Customary Court of Appeal
There is a Customary Court of Appeal for the Federal Capital Territory and any State that requires it. This Court has appellate and supervisory jurisdiction in civil proceedings involving questions of customary law and is comprised of a President and such number of Judges as the National Assembly or the State Houses of Assembly (as the case may be) may prescribe.
In addition to these courts created by the Constitution, there also exist Magistrate Courts, Disctrict Courts, Area Courts and Customary Courts established in various states by state laws. These courts are of limited jurisdiction as specified in their enabling laws and appeals from them lie to the High Court, Sharia Court of Appeal or Customary Court of Appeal as the case may be.