Berkeley, like his contemporaries Agatha Christie and Dorothy L. Sayers, "were fascinated by murder in real life," according to Martin Edwards, who makes another observation. True crime tales provided them with inspiration and motivation. (four) The Wychford Poisoning Case drew inspiration from the case of Florence Maybrick, who faced accusations of poisoning her husband, James Maybrick, and ultimately proved guilty of the crime. Both Edwards and Tony Medawar have mentioned this fact. Sheringham also alludes to numerous other true crime cases involving Edith Thompson and Frederick Bywaters, Frederick Seddon, Hawley Harvey Crippen, William Palmer, Edward William Pritchard, George Henry Lamson, Herbert Rowse Armstrong, Catherine Wilson, Maria van der Linden-Swanenburg (referred to in the novel as "Van de Leyden"), Marie Jeanneret (a Swiss nurse found guilty of murdering six persons and attempting to murder two others by poison), Steinie Morrison, Oscar Slater, Constance Kent, Alfred John Monson, and Madeleine Smith.

The Wychford Poisoning Case was dedicated to fellow crime writer E. M. Delafield.