The absence of powder marks, the disappearance of the pistol with which the mortal shot was fired, effectually eliminated the theory of suicide.
Yet, a man seated in a chair, and bent on self-destruction, might easily have inflicted the wound described by the Coroner's physician.

Before arriving at any definite conclusion, however, as to the position of the assassin when he sent the bullet into Whitmore's body, the detective decided to study the enlarged photograph of the wound which he had ordered the official photographer to make.
He found the picture on his desk at Police Headquarters.

Greig had preceded him by two hours to the building in Mulberry street, and was deep in the intricacies of the case when Britz summoned him.

He entered the room, followed a moment or two later, by Manning.
"What do you make of it ?" asked Britz, holding up the picture.
"Pretty jagged wound," commented Manning.
Britz produced a magnifying glass through which the three men examined the wound more critically.
"There are two perforations of the skin where the bullet entered," Britz pointed out.

"Undoubtedly they were made by the needle which I picked off the floor of Whitmore's office." "Well, what of that ?" asked the chief.
"It confirms my belief that I have solved the mystery of how Whitmore was killed." "I don't see it," snapped the chief.