The front of the building The murderer couldn’t leave through the front door of the building, without being seen, because the group of neighbors were coming up the stairs. The murderer couldn’t leave through the front or side windows because of the crowds in the street.
The chimneys were so small that even a large cat would not be able to pass through.
The murderer must have escaped through one of the two windows in the back of the room. They both appear to be the same. Both seem to have a nail that goes through the window frame into the wall. Dupin tries to open the window unobstructed.
The window opens. When he closes it, the spring catches….BUT there is no way to push the nail in. Therefore…. He pulls the nail out. He pushes the spring he finds under the windowsill.
The murderer must have escaped through the window partially obstructed by the bed!!! Sure enough, the nail was broken and the head of the nail came out in his hand. When the window was open, it appeared that the nail was still in the window frame.
…the windows at the back of the building! The murderer MUST have exited through …
Now let’s talk about the voices… The gruff voice “Sacre!” “Diable!” Obviously, a Frenchman!
And the shrill voice?? An Italian? A Russian? A Frenchman? Englishman? Spaniard? – A man? – A woman?