After 25 years of prosecuting and defending at the Criminal Bar, David was appointed the first Director of Revenue and Customs Prosecutions in April 2005. He headed the Revenue and Customs Prosecutions Office from its launch until the department was merged with the Crown Prosecution Service in January 2010.
David returned to the Bar in April 2011. He was appointed Director of the Serious Fraud Office on 21 April 2012.
David was called to the Bar in 1979; appointed Recorder in 1996 and took silk in 2000. He was appointed CB in the Queen's Birthday Honours 2011.