Sir Muir was Principal of the University of Glasgow from 2003 to 2009. Prior to his appointment at the University of Glasgow he was Permanent Secretary to the Scottish Executive. He was born in 1949 and was educated at The High School of Glasgow and Glasgow University, where he took a first class honours degree in Natural Philosophy. He is a Trustee of the Glasgow School of Art, a Member of the Board of the Moredun Research Institute, and the Chairman of the Dunedin Concert Trust. He was elected as a Fellow of the Royal Society of Edinburgh in 2000 and holds honorary degrees from the Universities of Strathclyde, Glasgow and Edinburgh.  His interests include music, food, wine and occasional golf.

Sir Muir was appointed until October 2011 and has been reappointed until September 2014.

Andrew Coyle is Professor of Prison Studies at King's college, University of London.  Between 1997 and 2005 he was founding Director of the International Centre for Prison Studies King's College.  He is a prisons adviser to several United Nations bodies and to the Council of Europe.  He is a member of the Foreign Secretary's Expert Panel against Torture and of the Administrative Justice and Tribunals Council. He worked for 25 years at a senior level in the prison services of the United Kingdom.  While in the Scottish Prison Service he was Governor of Greenock, Peterhead and Shotts Prisons.  Between 1991 and 1997 he was Governor of Brixton Prison in London. He was appointed a Companion of the Order of St Michael and St George in 2003 for his contribution to international penal reform.  He is a Fellow of King's College London.

Professor Coyle was reappointed in November 2011 for three years until 31 December 2014.

Elspeth MacArthur's background is in human resources. She was Director of Human Resources at the University of Edinburgh until 2007. Ms MacArthur is also a member of the Board of Management at the John Wheatley College, Glasgow and a Director of the Scottish Community Development Centre.  She is also a lay member of the Employment Tribunal (Scotland).

Ms MacArthur was re- appointed in July 2010 for three years.

Dr Ewart has a First Class Honours degree from Cambridge and a DPhil from York University. He joined the then Scottish Office in 1977, where his career began in the Education Department. In 1991 he became Deputy Director of the Scottish Courts Administration and guided the Scottish Court Service to agency status, becoming its first Chief Executive in 1994. In 1999 he returned to the Education Department, first as Head of Schools Group, and from 2002, as Head of the Education Department. From April 2007 until November 2009, he was Chief Executive of the Scottish Prison Service. Dr Ewart is now Director of the Scottish International Education Trust and a Board Member of the Scottish Ballet.

Dr Ewart was appointed in August 2010 for four years.

Lady Dorrian was appointed a Judge of the Supreme Courts in 2005, having served as a Temporary Judge since 2002.

She is a graduate of the University of Aberdeen (LLB). She was admitted to the Faculty of Advocates in 1981 and was Standing Junior Counsel to the Health and Safety Executive and Commission between 1987 and 1994.

Lady Dorrian served as Advocate Depute between 1988 and 1991, and as Standing Junior to the Department of Energy between 1991 and 1994.  Lady Dorrian was appointed Queen's Counsel in 1994. Between 1997 and 2001 she was a member of the Criminal Injuries Compensation Board.

Lady Dorrian was appointed in July 2011 for four years.

David Mackie was appointed Sheriff in 2002 and has been a resident Sheriff in Alloa since 2004. He is a graduate of Edinburgh University and from 1976 was in private practice as a solicitor. Called to the Scottish Bar in 1991, he practised as an Advocate until his appointment to the Shrieval bench. He was Standing Junior Counsel to the Ministry of Defence (Procurement) from 1996 to 2002. He is Chairman of the Edinburgh branch of SASO (Scottish Association for the Study of Offending) and sits on the National Competition Appeal Panel of the Scottish Rugby Union. A director and latterly chairman of Venture Trust from 2001 until 2011, he is now a Director of Chance4Change.

Sheriff Mackie was appointed to the Board from January 2013 to December 2017.

James McNeill, born in 1952, was educated at Dunoon Grammar School, Cambridge and Edinburgh Universities. He was admitted as an Advocate in 1978 and held the appointment of Standing Junior Counsel to the Inland Revenue in Scotland between 1988 and 1991, when he took silk. He sits as one of the Judges of the Courts of Appeal of Guernsey and Jersey and as a Convenor of the Presbyterial Commissions of the Church of Scotland. His principal outside interest is in music and between 2004 and 2010 he chaired the Music Committee of the Board of the Scottish International Piano Competition.

Mr McNeill was appointed in September 2012 for four years until September 2016.

Martin McAllister is a partner with Taylor and Henderson Solicitors based in Saltcoats, Ayrshire. He is a former President of The Law Society of Scotland and has convened several of its Committees including Legal Aid, Professional Practice and Professional Conduct. Mr McAllister is currently a part time tutor at the University of Strathclyde and a part time Convenor of The Mental Health Tribunal for Scotland.

Mr McAllister was appointed in September 2008 for three years and has been reappointed until August 2014.