Justice Arnold graduated from Victoria University of Wellington with a Bachelor of Arts and Master of Laws and New York University with an Master of Laws He taught criminal law at Victoria University of Wellington as well as at several Canadian universities, including Dalhousie University and the University of Calgary.
He was the Solicitor-General of New Zealand from 2000, before being made a judge of the Court of Appeal of New Zealand in 2006. He was elevated to the Supreme Court in June 2013. He became a barrister sole in 1994 and shortly thereafter, was appointed Queen's Counsel.
He was Solicitor-General between 2000 and 2006.
He was appointed a judge of the High Court and the Court of Appeal in May 2006.
