The story takes place during the stagecoach era of the 1880s, but all of Iris Meredith's clothes, i.e. knee length skirts, shoulder pads, high heel shoes, etc., are strictly in the contemporary 1940 mode, as well as her bobbed hair styles.
When Larry presents Larsen's confession as evidence, he says "Harper here can tell you all about it," but points directly to Larsen.