Gary Madden was a Metropolitan Police officer in London for 30 years. He has worked in a number of specialised units, based at New Scotland Yard, including counter-terrorism; hostage negotiation; kidnap and extortion; and international organised crime. Towards the end of his service he specialised in witness protection, in which he worked for seven years. During that time, he looked after a number of high profile cases. He retired in 2009 and is available to work as a Series and Script Consultant.