My father-in-law, Christopher Penfold, who has died aged 83, was an influential writer and script editor in British film and television. In a career spanning more than 40 years, he wrote or script-edited more than 300 hours of primetime television, including shows such as All Creatures Great and Small, Casualty, EastEnders, The Bill and the cult classic Space: 1999.

Chris also served as series editor for 78 episodes (2000-12) of ITV’s Midsomer Murders, one of the most successful long-form drama series in television history. Fellow Midsomer writers Nick Martin and Barry Simner said: “Chris ushered the series into being and coined the credo that underpinned the show’s enormous success – ‘Fun with murder’ – and writers did have fun. Script meetings in Penfold’s living room would generate gales of laughter as ever more macabre murders were concocted.”