At least since 1282, when a coroner called a surgeon to advise whether an arrow injury to the chest could be fatal (Sayles 1936), doctors have been needed to assist the administration of justice. Dr Andrew Duncan, Senior, recognised this in 1795 in his University of Edinburgh lectures on forensic medicine: ‘Many questions come before the Courts … where the opinion of medical practitioners is necessary either for the exculpation of innocence or the detection of guilt … an opinion consistent with truth and with justice.’ This duty was identified by Percival (1803, p. 120): ‘It is a complaint made by coroners, magistrates and judges, that medical gentlemen are often reluctant in the performance of the offices, required from them as citizens qualified by professional knowledge, to aid the execution of public justice.’