Aaron commenced employment as a Law Clerk in January 1961 for a firm of Melbourne Solicitors. Three years later he joined the Criminal Law Branch of the then Crown Solicitors Office conducted by Mr. Thomas F. Mornane. Whilst there employed he instructed and assisted permanent Prosecutors for the Queen and other counsel retained to prosecute criminal trials both in Melbourne and on circuit. In 1968 Aaron commenced a law course conducted by the Council of Legal Education and became Articled to Kenneth Charles Haines for a period of four years. During that period he was given the care and conduct of both civil and criminal matters on behalf of his principal. In March 1972 he was admitted to Practice and immediately came to the Bar where he read with Jeff Sher.

Aaron has developed an extensive practice in criminal law appearing in every jurisdiction in Victoria and in the High Court. He has regularly appeared in the Court of Criminal Appeal, now the Court of Appeal, and is briefed in matters dealing with homicide, commercial fraud and prosecutions related to drugs. He was Counsel for the Defence in the notorious "Mr. Stinky" case and acted for Nathan Avent whose trial attracted a great deal of public notoriety in relation to the publicising and televising of criminal trials. He also appeared as Counsel for David Albion who together with his mother Heather Osland were charged with the murder of Frank Osland. A jury later acquitted David Albion of that murder.

Aaron is also admitted in N.S.W. He has had considerable civil and common law experience and has appeared on a number of occasions in the Full Court of the Family Court.

Aaron was the Bar Representative on the Steering Committee of the Criminal Delay Reduction Progamme chaired by the then Chief Justice, Sir John Young. Has also served a term as Secretary to the Criminal Bar Association of Victoria and was one of its founding members.

Professional Standards Act 2003 [Vic] "Liability limited by a scheme approved under Professional Standards Legislation."