"The Happy Valley" was broadcast several months before the premiere of "White Mischief," a theatrical film on the same subject matter.
"Elspeth Huxley: A Biography" by Christine Nicholls, published in 2007, names the killer after 66 years. Coincidently, there was renewed interest in the murder after fashion designer Isabella Blow, granddaughter of Delves Broughton, took her own life the same year.