Dupin has advertised the safe capture of the animal, news that he believes will draw out its owner. Dupin adds that the owner must be a sailor, since, at the base of the lightning rod, he found a ribbon knotted in a way unique to naval training. 

When the sailor arrives, Dupin draws his pistol and demands all the information he knows about the murders. He assures the sailor that he believes him to be innocent. The sailor describes how the animal, grasping a razor, escaped from its closet one night and disappeared from his apartment. The sailor followed the orangutan and watched him climb the lightning rod and leap into the window. Because he does not possess the animal’s agility, the sailor could only watch the animal as it slashed Madame L’Espanaye and choked Camille. Before escaping the apartment, the animal threw Madame L’Espanaye’s body to the courtyard below. The sailor thus confirms the identity of the mysterious voices—the deep voice was his own, and the shrill shrieks were that of the orangutan. 

When informed of Dupin’s solution, the police release Le Bon. The prefect is unable to conceal his chagrin at being outwitted by Dupin. He is happy to have the crime solved, but he is sarcastic, rather than grateful, about Dupin’s assistance. Dupin comments, in conclusion, that the prefect is a man of ingenuity, not analysis.