Because none of the witnesses can agree on the language the murderer spoke, Dupin concludes they were not hearing a human voice at all. He and the narrator examine the house thoroughly; the following day, Dupin dismisses the idea of both Le Bon's guilt and a robbery motive, citing the fact that the gold was not taken from the room. He formulates a method by which the murderer could have entered the room and killed both women, involving an agile climb up a lightning rod and a leap to a set of open window shutters. Showing an unusual tuft of hair he recovered from the scene, and demonstrating the impossibility of the daughter being strangled by a human hand, Dupin concludes that an "Ourang-Outang" (orangutan) killed the women. He has placed an advertisement in the local newspaper asking if anyone has lost such an animal, and a sailor soon arrives looking for it.