This infographics by Dorothy Gambrell for Bloomberg is delicious: Who Did What in Every Agatha Christie Murder Novel.

In Agatha Christie’s novels, murder and financial fraud are often intertwined. The murderers are more likely to be men, are partial to poison, and frequently commit the crime as part of a scam such as winning an inheritance.

But let’s dig deeper into this stylized picture of a life writing about crime. (Stop reading here if you are planning to read Christie’s novels)

Agatha Christie published her first detective novel in 1920, 100 years ago. The Mysterious Affair at Styles was written in 1916, and it already featured her famous Belgian detective with “magnificent moustaches”, Hercule Poirot.

If she always had clear that males and poison were the bread and butter of crime stories, her position (or preference) regarding murderer’s age, profession, relationship with the victim, and motive changed in a significant way.

At the very beginning she seemed to think that young adults in many different professions and with many different relationships with her victims made good murderers and crime stories. Fifty years later, by the end of her long writing track record, she had changed her mind and was concentrated on a much more limited range of options. You’d better bet that the murderer was the elder member of the victim’s family, who was retired or without known profession. And perhaps what’s more curious (to me) is that while for most of her writing life inheritance was the main motive, in her last years it abruptly changed to jealousy.

Having written more than 60 novels dealing with crime, we must assume she knew a couple of words about it. I wonder if she would have kept her positions for another fifty years until 2020, or she would have changed with the ebb and flow of history or her memory. If she was still exploring by the end of her life, or have found a timeless portrayal, the one at the edge of these colourful charts… The perfect crime, so to speak.