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.

Sheriff Ross was appointed a Sheriff in 1997, serving at Linlithgow until 2000 and since then at Dumfries.  He is a graduate of Edinburgh University and qualified as a solicitor in 1973.  From 1975 until 1997 he was a partner in the firm of Gillespie, Gifford & Brown, Solicitors, Dumfries.  He served on the Council of the Law Society of Scotland from 1987 until 1996, convening the Complaints and Guarantee Fund Committees.  He was President of the Law Society of Scotland in 1994/5.  He sat as a Temporary Sheriff between 1987 and 1997 and was a member of the Scottish Legal Aid Board between 2004 and 2010.

Sheriff Ross' appointment has been extended until 31 December 2012. 

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.