The Body in the Library (1942) concerns the murders of two girls of outwardly similar appearance.

One of them was an 18-year-old dancer, and the other was a 16-year-old Girl Guide with aspirations to an acting career.

The identities of the two victims were deliberately left ambiguous by the killers. 

Jane Marple eventually discovers that the dancer was the intended adoptive daughter and heiress to a wealthy man. She starts suspecting the other potential heirs to the old man’s fortune. …

Somewhat too complicated for me. I didn’t find myself assuming that everyone was the killer as I typically do in Christie stories.

Many of these old TV shows are available as full episodes on YouTube.

Click PLAY or watch it on YouTube.