The Hon Mark Weinberg was admitted to practice in New South Wales in 1974, and in Victoria in 1975. In 1975 he joined the academic staff of the University of Melbourne, where he held various positions in the Faculty of Law, culminating in Dean of the Faculty from 1984 to 1985. He was Commonwealth Director of Public Prosecutions from 1988 to 1991. Mark Weinberg was appointed to the Court of Appeal, Supreme Court of Victoria in July 2008. His Honour was a judge of the Federal Court of Australia from 1998 to 2008 and previously held a series of additional judicial and other appointments. In 2017, he was appointed an Officer of the Order of Australia for distinguished service to the judiciary and to the law, particularly through reforms to criminal law and procedure, to legal education in Victoria and to the administration of justice in Fiji and Norfolk Island. In October 2017 he was awarded the degree of LLD (Honoris Causa) by Monash University. On 9 May 2018, he retired from the Court of Appeal of the Supreme Court of Victoria after 10 years of service. He continued to hear cases as a reserve Judge. Following the release of the Brereton Report, in December 2020, he was appointed by the then Home Affairs Minister Peter Dutton as the Special Investigator to investigate alleged war crimes by Australian soldiers in Afghanistan.