The High Court of Justiciary (Scottish Gaelic: Àrd-chùirt a' Cheartais) is the supreme criminal court in Scotland. The High Court is both a trial court and a court of appeal. As a trial court, the High Court sits on circuit at Parliament House or in the adjacent Justiciary Building (the former Sheriff Court building) in the Old Town in Edinburgh, or in dedicated buildings in Glasgow and Aberdeen. The High Court sometimes sits in various smaller towns in Scotland, where it uses the local sheriff court building. As an appeal court, the High Court sits only in Edinburgh. On one occasion the High Court of Justiciary sat outside Scotland, at Zeist in the Netherlands during the Pan Am Flight 103 bombing trial, as the Scottish Court in the Netherlands. At Zeist the High Court sat both as a trial court, and an appeal court for the initial appeal by Abdelbaset al-Megrahi.
The president of the High Court is the Lord Justice General, who holds office ex officio by virtue of being Lord President of the Court of Session, and his depute is the Lord Justice Clerk. The remaining judges are the Lords Commissioners of Justiciary, who hold office ex officio by virtue of being appointed as Senators of the College of Justice and judges of the Court of Session. As a court of first instance trials are usually heard with a jury of 15 and a single Lord Commissioner of Justiciary; the jury can convict on a majority verdict. In some cases, such as the trial of Abdelbaset al-Megrahi and Lamin Khalifah Fhimah for the bombing of Pan Am Flight 103, a trial can be heard by a bench of judges alone; sitting without a jury. As an appeal court the hearings are always without a jury, with two judges sitting to hear an appeal against sentence, and three judges sit to hear an appeal against conviction.