A subgenre of crime films in which the focus of the plot is on a crime committed, primarily in a closed setting, and one or more characters act as detectives to try to determine the culprit among multiple suspects, all with a motive for doing so or a relationship to the victim. Agatha Christie's works are the most representative example, as are modern films such as the "Knives Out" series. They tend to contain a certain sense of humor and don't delve as deeply into the dramatic aspect.