The model village is Bekonscot Model Village in Beaconsfield, England.
The actress Olivia Colman that plays Bernice, was in the movie Hot Fuzz (2007). This movie also featured a miniature village and a murder investigation. In this episode, the model village is the initial crime scene; in Hot Fuzz, the model village is the setting of the climax.
The schoolchildren sing "And the Green Grass Grows All Around". A more randy version of that song, "The Maypole Song" is sung by the village children in The Wicker Man (1973).
The Compton sisters' house also featured in Dead Letters (2006) S9 E2 as the home of the doctor, played by Simon Callow.