John was called to the Bar (Gray’s Inn) in 1980. He practised in the United Kingdom and served in the Army Legal Corps as captain and was stationed in Germany. He was then called to the Hong Kong Bar in 1985 and has been practising in Hong Kong since. John specialises in criminal cases.

John has appeared in many high profiled court cases for both prosecution and defence, both at trial and on appeal. He has also appeared in landmark commercial crime cases for many years. He is a part time lecturer at the University of Hong Kong and was a lecturer at the City University.