Closed circle of suspects

[1][2][3] Less precisely, this subgenre – works with the closed circle literary device – is simply known as the "classic", "traditional" or "cozy" detective fiction.

[4][5] It refers to a situation in which for a given crime (usually a murder), there is a quickly established, limited number of suspects, each with credible means, motive, and opportunity.

[9][10] Other writers of that period, dating to the first half of the 20th century, a time known as the Golden Age of Detective Fiction (or more general, mystery fiction), reliant on the closed circle and related literary devices include Dorothy L. Sayers, G. K. Chesterton, Margery Allingham, Ngaio Marsh and Americans S. S. Van Dine and Ellery Queen.

Certain settings are frequently represented in the genre, typically involving upper-class characters to whose properties outsiders have limited access.

[8] After the Second World War, the closed circle mystery became less common as other types of crime novels rose to prominence;[16] nonetheless, writers such as Rex Stout, Lucille Kallen, Cyril Hare, Jonathan Gash, and Simon Brett have employed the device in their fiction.