High Quality Content by WIKIPEDIA articles! Midsomer Murders is a British television detective drama that has aired on ITV since 1997. The show is based on the books by Caroline Graham, as originally adapted by Anthony Horowitz. The lead character is DCI Tom Barnaby (John Nettles) who works for Causton CID. When Nettles left the show in 2011 he was replaced by actor Neil Dudgeon who plays Tom`s younger cousin DCI John Barnaby. The stories revolve around the Barnabys` efforts to solve the numerous murders that take place in the fictional English county of Midsomer. Barnaby has had several Sergeants throughout the run of the show: DS Gavin Troy (Daniel Casey), DS Dan Scott (John Hopkins) and currently DS Ben Jones (Jason Hughes).