Brett joined the Metropolitan Police Service in 1978. After retiring as the Head of Counter Terrorism for the City of London Police in 2008. As Head of Counter Terrorism, he also had national responsibility for countering hostile reconnaissance against the financial services and critical national infrastructure within a successful and continuing public/private UK wide partnership. Brett is today the Chief Executive of the City Security and Resilience Networks (CSARN) covering the UK and Australia; Chairman of Paratum (Counter Terrorism Engineering); Chairman of X-Forces Police; Managing Director of Valentis Bridge Ltd; Chairman of the London Chamber Defence and Security Committee and is a member of the London Board of Crimestoppers. His companies address the full spectrum of counter terrorism, counter corporate espionage, artificial intelligence, engineering, business continuity, crisis leadership, risk analysis, disaster recovery and emergency planning issues featuring both nationally and internationally on defence and organisational solutions.