The High Court is both a court of first instance and a court of appeal. As a court of first instance, the High Court sits mainly in Parliament House, or in the former Sheriff Court building, in Edinburgh, but also sits from time to time at various other locations in Scotland. As a court of appeal, it sits only in Edinburgh.
The judges of the High Court are the same ones who sit in the Court of Session, Scotland's supreme civil court. The Court of Session's Lord President is also the High Court's Lord Justice General. The Lord Justice Clerk holds his or her office in both courts. The remaining judges are referred to as Lords Commissioners of Justiciary in the context of the High Court, and Lords of Council and Session or Senators of the College of Justice in the context of the Court of Session.
When sitting as a court of first instance, that is, when hearing a case for the first time rather than on appeal, a single Lord Commissioner of Justiciary usually presides (although two or more judges may sit in important or difficult cases) with a jury of fifteen individuals. Under the Scottish legal system, the jury need not return a unanimous verdict; a majority verdict may also be used. The Scottish legal system also permits a verdict of 'not proven' as well as verdicts of 'guilty' or 'not guilty'.
The High Court has jurisdiction over all crimes in Scotland unless restricted by statute. In practice, however, the High Court generally deals with crimes, such as murder and rape, in which it has exclusive jurisdiction, and other serious crimes.
Appeals may be made to the High Court of Justiciary sitting as the Court of Criminal Appeal from the lower courts in criminal cases. An appeal may also be made to the High Court if the High Court itself heard the case at first instance. Two judges sit to hear an appeal against sentence, and three judges sit to hear an appeal against conviction.
There is no further appeal from the High Court's decision on appeal, in contrast to the Court of Session, from which it is possible to appeal to the House of Lords, the UK's highest court. However, appeals under the Human Rights Act and devolution appeals under the Scotland Act are heard by the Judicial Committee of the Privy Council. The members of the Judicial Committee also sit in the House of Lords as the Lords of Appeal in Ordinary.