The overcoat is initially presented as a clue to the murderer’s appearance, but the plethora of overcoats in the play make it a symbol of interchangeable identities and disguise. At the beginning of the play, a radio announcer reporting on the murder mentions that the police are looking for a suspect with a “dark overcoat” (2). Shortly thereafter, Mollie and Giles both enter the room, taking off their overcoats. The next time the radio comes on, the announcer again mentions the murderer’s overcoat as Mollie picks up Giles’s coat. This is the second connection between a verbal description of the item and the physical presence of it, which creates a red herring that Giles is the murderer.

The overcoat is also mentioned in the newspaper that Miss Casewell reads, and she begins to question its usefulness as a clue. She says the police description would “Fit pretty well anyone, wouldn’t it” (11). This happens shortly after Miss Casewell takes off her overcoat, throwing it to Giles, who “catches it” (11). When Trotter arrives, he mentions that there are “three darkish overcoats hanging up in the hall” (32) of Monkswell Manor. This number of coats symbolizes how the murderer can easily take on a disguise, and how people wear a variety of identities.