“The police surgeon found that he had been dead about twelve hours. He had been killed by a single blow, struck from behind, with some heavy implement, and a jemmy which lay on the floor beside him fitted the wound exactly. The deceased wore a dressing-gown and no collar, and a bedroom candlestick lay upside down on the floor, although gas was laid on in the room; and as the window of the office appears to have been forced with the jemmy that was found, and there were distinct footprints on the flower-bed outside the window, the police think that the deceased was undressing to go to bed when he was disturbed by the noise of the opening window; that he went down to the office and, as he entered, was struck down by the burglar who was lurking behind the door. On the window-glass the police found the greasy impression of an open right hand, and, as you know, the finger-prints were identified by the experts as those of an old convict named Belfield. As you also know, I proved that those finger-prints were, in reality, forgeries, executed with rubber or gelatine stamps. That is an outline of the case.”
The close of this recital brought our meal to an end, and we prepared for our visit to the scene of the crime. Thorndyke slipped into his pocket his queer outfit—somewhat like that of a field geologist—locked up the photographs, and we set forth by way of the Embankment.
“The police have no clue, I suppose, to the identity of the murderer, now that the finger-prints have failed?” I asked, as we strode along together.
“I expect not,” he replied, “though they might have if they examined their material. I made out a rather interesting point this morning, which is this: the man who made those sham finger-prints used two stamps, one for the thumb and the other for the four fingers; and the original from which those stamps were made was the official finger-print form.”
“How did you discover that?” I inquired.
“It was very simple. You remember that Mr. Singleton of the Finger-print Department sent me, by Superintendent Miller, two photographs, one of the prints on the window and one of the official form with Belfield’s finger-prints on it. Well, I have compared them and made the most minute measurements of each, and they are obviously duplicates. Not only are all the little imperfections on the form—due to defective inking—reproduced faithfully on the window-pane, but the relative positions of the four fingers on both cases agree to the hundredth of an inch. Of course the thumb stamp was made by taking an oval out of the rolled impression on the form.”
“Then do you suggest that this murder was committed by some one connected with the Finger-print Department at Scotland Yard?”
“Hardly. But some one has had access to the forms. There has been leakage somewhere.”
When we arrived at the little detached house in which the murdered man had lived, the door was opened by an elderly woman, and our friend, Superintendent Miller, greeted us in the hall.
“We are all ready for you, doctor,” said he. “Of course, the things have all been gone over once, but we are turning them out more thoroughly now.” He led the way into the small, barely-furnished office in which the tragedy had occurred. A dark-stain on the carpet and a square hole in one of the window-panes furnished memorials of the crime, which were supplemented by an odd assortment of objects laid out on the newspaper-covered table. These included silver teaspoons, watches, various articles of jewellery, from which the stones had been removed—none of them of any considerable value—and a roughly-made jemmy.