Midsomer Murders star John Nettles' life off screen 15 years after leaving the popular ITV show John Nettles was best known for his role as DCI Tom Barnaby in Midsomer Murders, which he played for 14 years John Nettles as DCI Tom Barnaby (Image: ITV ) John Nettles may have left Midsomer Murders 15 years ago, but he will always be linked with the popular ITV crime drama. Today, the 81-year-old, best known for his role as DCI Tom Barnaby, leads a peaceful life in Devon, while Midsomer Murders continues to prosper after 25 years, with Neil Dudgeon, John's successor,...