The back page of the newspaper read by Miss Marple has a headline stating "Strathspey 25-1 Winner of the Cesarewitch." The Cesarewitch is a British "flat" (no jumps) race for thoroughbreds, run in Newmarket, which the horse Strathspey did indeed win, in 1949.
The song "Sing a Song of Sixpence" being sung periodically through the film was sung by the young Aled Jones.
Timothy West plays Rex Fortescue in this version while his wife Prunella Scales would later play Miss Effie Ramsbottom in the ITV adaptation Miss Marple: Une poignée de seigle (2008).
When Miss Marple and Miss Henderson recite "The murderer rising with the light..." they are quoting the King James version of the Book of Job (24:14).
First appearance of Mrs. Brogan, Rhoda Lewis, who runs the general store/newsagent at St. Mary Mead. This character was created for the series and also appears in Miss Marple: Le train de 16 h 50 (1987) and Miss Marple: The Mirror Crack'd from Side to Side (1992).