Poirot explains that he and Race began their investigation with the assumption that Linnet’s murder was spontaneous rather than planned: “[s]omebody wished to remove Linnet Doyle and had seized their opportunity to do so at a moment when the crime would almost certainly be attributed to Jacqueline de Bellefort” (387). Therefore, the murderer must have witnessed Jackie shooting Simon in the saloon and then stolen the pistol after everyone had left.

However, this was the wrong assumption. The murder was in fact thoroughly worked out in advance.

As Poirot has been indicating, Jackie’s discarded pistol is the key clue. Poirot recalls that Linnet’s gunshot wound indicated that she had been shot point-blank; there were burns around the point of entry. However, when the pistol was recovered later, it was wrapped in a velvet stole, through which it had been fired. If the pistol had been wrapped in the stole when Linnet was murdered, there would have been no burns on her skin around the gunshot wound. Therefore, the killer did not wrap the gun in the stole to kill Linnet, nor was the gun wrapped up when Jackie shot Simon. This means that a third shot was fired, with the gun wrapped in the stole.