The Red Thumb Mark

He ascended the stairs leading to the dais and addressed a few words to the judge, who glanced in our direction and nodded, whereupon we both gleefully followed our counsel, Polton carrying the box and beaming with delight.

The judge's table was provided with a shallow drawer which pulled out at the side and which accommodated the box comfortably, leaving the small table-top free for the papers. When the lid of the box was raised, there were displayed a copper inking-slab, a small roller and the twenty-four "pawns" which had so puzzled Polton, and on which he now gazed with a twinkle of amusement and triumph.

"Are those all stamps?" inquired the judge, glancing curiously at the array of turned-wood handles.

"They are all stamps, my lord," replied Thorndyke, "and each is taken from a different impression of the prisoner's thumb."

"But why so many?" asked the judge.

"I have multiplied them," answered Thorndyke, as he squeezed out a drop of finger-print ink on to the slab and proceeded to roll it out into a thin film, "to avoid the tell-tale uniformity of a single stamp. And I may say," he added, "that it is highly important that the experts should not be informed that more than one stamp has been used."

"Yes, I see that," said the judge. "You understand that, Sir Hector," he added, addressing the counsel, who bowed stiffly, clearly regarding the entire proceeding with extreme disfavour.

Thorndyke now inked one of the stamps and handed it to the judge, who examined it curiously and then pressed it on a piece of waste paper, on which there immediately appeared a very distinct impression of a human thumb.

"Marvellous!" he exclaimed. "Most ingenious! Too ingenious!" He chuckled softly and added, as he handed the stamp and the paper to the foreman of the jury: "It is well, Dr. Thorndyke, that you are on the side of law and order, for I am afraid that, if you were on the other side, you would be one too many for the police. Now, if you are ready, we will proceed. Will you, please, stamp an impression in square number three."

Thorndyke drew a stamp from its compartment, inked it on the slab, and pressed it neatly on the square indicated, leaving there a sharp, clear thumb-print.

The process was repeated on nine other squares, a different stamp being used for each impression. The judge then marked the ten corresponding squares of the other two sheets of paper, and having checked them, directed the foreman to exhibit the sheet bearing the false thumb-prints to the jury, together with the marked sheet which they were to retain, to enable them to check the statements of the expert witnesses. When this was done, the prisoner was brought from the dock and stood beside the table. The judge looked with a curious and not unkindly interest at the handsome, manly fellow who stood charged with a crime so sordid and out of character with his appearance, and I felt, as I noted the look, that Reuben would, at least, be tried fairly on the evidence, without prejudice or even with some prepossession in his favour.

With the remaining part of the operation Thorndyke proceeded carefully and deliberately. The inking-slab was rolled afresh for each impression, and, after each, the thumb was cleansed with petrol and thoroughly dried; and when the process was completed and the prisoner led back to the dock, the twenty squares on the paper were occupied by twenty thumb-prints, which, to my eye, at any rate, were identical in character.

The judge sat for near upon a minute poring over this singular document with an expression half-way between a frown and a smile. At length, when we had all returned to our places, he directed the usher to bring in the witnesses.

I was amused to observe the change that had come over the experts in the short interval. The confident smile, the triumphant air of laying down a trump card, had vanished, and the expression of both was one of anxiety, not unmixed with apprehension. As Mr. Singleton advanced hesitatingly to the table, I recalled the words that he had uttered in his room at Scotland Yard; evidently his scheme of the game that was to end in an easy checkmate, had not included the move that had just been made.

"Mr. Singleton," said the judge, "here is a paper on which there are twenty thumb-prints. Ten of them are genuine prints of the prisoner's left thumb and ten are forgeries. Please examine them and note down in writing which are the true prints and which are the forgeries. When you have made your notes the paper will be handed to Mr. Nash."

"Is there any objection to my using the photograph that I have with me for comparison, my lord?" asked Mr. Singleton.

"I think not," replied the judge. "What do you say, Mr. Anstey?"

"No objection whatever, my lord," answered Anstey.

Mr. Singleton accordingly drew from his pocket an enlarged photograph of the thumb-print and a magnifying glass, with the aid of which he explored the bewildering array of prints on the paper before him; and as he proceeded I remarked with satisfaction that his expression became more and more dubious and worried. From time to time he made an entry on a memorandum slip beside him, and, as the entries accumulated, his frown grew deeper and his aspect more puzzled and gloomy.

At length he sat up, and taking the memorandum slip in his hand, addressed the judge.

"I have finished my examination, my lord."

"Very well. Mr. Nash, will you kindly examine the paper and write down the results of your examination?"

"Oh! I wish they would make haste," whispered Juliet. "Do you think they will be able to tell the real from the false thumb-prints?"

"I can't say," I replied; "but we shall soon know. They looked all alike to me."

Mr. Nash made his examination with exasperating deliberateness, and preserved throughout an air of stolid attention; but at length he, too, completed his notes and handed the paper back to the usher.

"Now, Mr. Singleton," said the judge, "let us hear your conclusions. You have been sworn."

Mr. Singleton stepped into the witness-box, and, laying his notes on the ledge, faced the judge.

"Have you examined the paper that was handed to you?" asked Sir Hector Trumpler.

"I have."

"What did you see on the paper?"

"I saw twenty thumb-prints, of which some were evident forgeries, some were evidently genuine, and some were doubtful."

"Taking the thumb-prints seriatim, what have you noted about them?"

Mr. Singleton examined his notes and replied—"The thumb-print on square one is evidently a forgery, as is also number two, though it is a passable imitation. Three and four are genuine; five is an obvious forgery. Six is a genuine thumb-print; seven is a forgery, though a good one; eight is genuine; nine is, I think, a forgery, though it is a remarkably good imitation. Ten and eleven are genuine thumb-marks; twelve and thirteen are forgeries; but as to fourteen I am very doubtful, though I am inclined to regard it as a forgery. Fifteen is genuine, and I think sixteen is also; but I will not swear to it. Seventeen is certainly genuine Eighteen and nineteen I am rather doubtful about, but I am disposed to consider them both forgeries. Twenty is certainly a genuine thumb-print."

As Mr. Singleton's evidence proceeded, a look of surprise began to make its appearance on the judge's face, while the jury glanced from the witness to the notes before them and from their notes to one another in undisguised astonishment.

As to Sir Hector Trumpler, that luminary of British jurisprudence was evidently completely fogged; for, as statement followed statement, he pursed up his lips and his broad, red face became overshadowed by an expression of utter bewilderment.

For a few seconds he stared blankly at his witness and then dropped on to his seat with a thump that shook the court.

"You have no doubt," said Anstey, "as to the correctness of your conclusions? For instance, you are quite sure that the prints one and two are forgeries?"

"I have no doubt."

"You swear that those two prints are forgeries?"

Mr. Singleton hesitated for a moment. He had been watching the judge and the jury and had apparently misinterpreted their surprise, assuming it to be due to his own remarkable powers of discrimination; and his confidence had revived accordingly.

"Yes," he answered; "I swear that they are forgeries."

Anstey sat down, and Mr. Singleton, having passed his notes up to the judge, retired from the box, giving place to his colleague.

Mr. Nash, who had listened with manifest satisfaction to the evidence, stepped into the box with all his original confidence restored. His selection of the true and the false thumb-prints was practically identical with that of Mr. Singleton, and his knowledge of this fact led him to state his conclusions with an air that was authoritative and even dogmatic.

"I am quite satisfied of the correctness of my statements," he said, in reply to Anstey's question, "and I am prepared to swear, and do swear, that those thumb-prints which I have stated to be forgeries, are forgeries, and that their detection presents no difficulty to an observer who has an expert acquaintance with finger-prints."

"There is one question that I should like to ask," said the judge, when the expert had left the box and Thorndyke had re-entered it to continue his evidence. "The conclusions of the expert witnesses—manifestly bona fide conclusions, arrived at by individual judgement, without collusion or comparison of results—are practically identical. They are virtually in complete agreement. Now, the strange thing is this: their conclusions are wrong in every instance" (here I nearly laughed aloud, for, as I glanced at the two experts, the expression of smug satisfaction on their countenances changed with lightning rapidity to a ludicrous spasm of consternation); "not sometimes wrong and sometimes right, as would have been the case if they had made mere guesses, but wrong every time. When they are quite certain, they are quite wrong; and when they are doubtful, they incline to the wrong conclusion. This is a very strange coincidence, Dr. Thorndyke. Can you explain it?"

Thorndyke's face, which throughout the proceedings had been as expressionless as that of a wooden figurehead, now relaxed into a dry smile.

"I think I can, my lord," he replied. "The object of a forger in executing a forgery is to produce deception on those who shall examine the forgery."

"Ah!" said the judge; and his face relaxed into a dry smile, while the jury broke out into unconcealed grins.

"It was evident to me," continued Thorndyke, "that the experts would be unable to distinguish the real from the forged thumb-prints, and, that being so, that they would look for some collateral evidence to guide them. I, therefore, supplied that collateral evidence. Now, if ten prints are taken, without special precautions, from a single finger, it will probably happen that no two of them are exactly alike; for the finger being a rounded object of which only a small part touches the paper, the impressions produced will show little variations according to the part of the finger by which the print is made. But a stamp such as I have used has a flat surface like that of a printer's type, and, like a type, it always prints the same impression. It does not reproduce the finger-tip, but a particular print of the finger, and so, if ten prints are made with a single stamp, each print will be a mechanical repetition of the other nine. Thus, on a sheet bearing twenty finger-prints, of which ten were forgeries made with a single stamp, it would be easy to pick out the ten forged prints by the fact that they would all be mechanical repetitions of one another; while the genuine prints could be distinguished by the fact of their presenting trifling variations in the position of the finger.

"Anticipating this line of reasoning, I was careful to make each print with a different stamp and each stamp was made from a different thumb-print, and I further selected thumb-prints which varied as widely as possible when I made the stamps. Moreover, when I made the real thumb-prints, I was careful to put the thumb down in the same position each time as far as I was able; and so it happened that, on the sheet submitted to the experts, the real thumb-prints were nearly all alike, while the forgeries presented considerable variations. The instances in which the witnesses were quite certain were those in which I succeeded in making the genuine prints repeat one another, and the doubtful cases were those in which I partially failed."

"Thank you, that is quite clear," said the judge, with a smile of deep content, such as is apt to appear on the judicial countenance when an expert witness is knocked off his pedestal. "We may now proceed, Mr. Anstey."

"You have told us," resumed Anstey, "and have submitted proofs, that it is possible to forge a thumb-print so that detection is impossible. You have also stated that the thumb-print on the paper found in Mr. Hornby's safe is a forgery. Do you mean that it may be a forgery, or that it actually is one?"

"I mean that it actually is a forgery."

"When did you first come to the conclusion that it was a forgery?"

"When I saw it at Scotland Yard. There are three facts which suggested this conclusion. In the first place the print was obviously produced with liquid blood, and yet it was a beautifully clear and distinct impression. But such an impression could not be produced with liquid blood without the use of a slab and roller, even if great care were used, and still less could it have been produced by an accidental smear.

"In the second place, on measuring the print with a micrometer, I found that it did not agree in dimensions with a genuine thumb-print of Reuben Hornby. It was appreciably larger. I photographed the print with the micrometer in contact and on comparing this with a genuine thumb-print, also photographed with the same micrometer in contact, I found that the suspected print was larger by the fortieth of an inch, from one given point on the ridge-pattern to another given point. I have here enlargements of the two photographs in which the disagreement in size is clearly shown by the lines of the micrometer. I have also the micrometer itself and a portable microscope, if the Court wishes to verify the photographs."

"Thank you," said the judge, with a bland smile; "we will accept your sworn testimony unless the learned counsel for the prosecution demands verification."

He received the photographs which Thorndyke handed up and, having examined them with close attention, passed them on to the jury.

"The third fact," resumed Thorndyke, "is of much more importance, since it not only proves the print to be a forgery, but also furnishes a very distinct clue to the origin of the forgery, and so to the identity of the forger." (Here the court became hushed until the silence was so profound that the ticking of the clock seemed a sensible interruption. I glanced at Walter, who sat motionless and rigid at the end of the bench, and perceived that a horrible pallor had spread over his face, while his forehead was covered with beads of perspiration.) "On looking at the print closely, I noticed at one part a minute white mark or space. It was of the shape of a capital S and had evidently been produced by a defect in the paper—a loose fibre which had stuck to the thumb and been detached by it from the paper, leaving a blank space where it had been. But, on examining the paper under a low power of the microscope, I found the surface to be perfect and intact. No loose fibre had been detached from it, for if it had, the broken end or, at least, the groove in which it had lain, would have been visible. The inference seemed to be that the loose fibre had existed, not in the paper which was found in the safe, but in the paper on which the original thumb-mark had been made. Now, as far as I knew, there was only one undoubted thumb-print of Reuben Hornby's in existence—the one in the 'Thumbograph.' At my request, the 'Thumbograph' was brought to my chambers by Mrs. Hornby, and, on examining the print of Reuben Hornby's left thumb, I perceived on it a minute, S-shaped white space occupying a similar position to that in the red thumb-mark; and when I looked at it through a powerful lens, I could clearly see the little groove in the paper in which the fibre had lain and from which it had been lifted by the inked thumb. I subsequently made a systematic comparison of the marks in the two thumb-prints; I found that the dimensions of the mark were proportionally the same in each—that is to say, the mark in the 'Thumbograph' print had an extreme length of 26/1000 of an inch and an extreme breadth of 14.5/1000 of an inch, while that in the red thumb-mark was one-fortieth larger in each dimension, having an extreme length of 26.65/1000 of an inch and an extreme breadth of 14.86/1000 of an inch; that the shape was identical, as was shown by superimposing tracings of greatly enlarged photographs of each mark on similar enlargements of the other; and that the mark intersected the ridges of the thumb-print in the same manner and at exactly the same parts in the two prints."

"Do you say that—having regard to the facts which you have stated—it is certain that the red thumb-mark is a forgery?"

"I do; and I also say that it is certain that the forgery was executed by means of the 'Thumbograph.'"

"Might not the resemblances be merely a coincidence?"

"No. By the law of probabilities which Mr. Singleton explained so clearly in his evidence, the adverse chances would run into untold millions. Here are two thumb-prints made in different places and at different times—an interval of many weeks intervening. Each of them bears an accidental mark which is due not to any peculiarity of the thumb, but to a peculiarity of the paper. On the theory of coincidences it is necessary to suppose that each piece of paper had a loose fibre of exactly identical shape and size and that this fibre came, by accident, in contact with the thumb at exactly the same spot. But such a supposition would be more opposed to probabilities even than the supposition that two exactly similar thumb-prints should have been made by different persons. And then there is the further fact that the paper found in the safe had no loose fibre to account for the mark."

"What is your explanation of the presence of defibrinated blood in the safe?"

"It was probably used by the forger in making the thumb-print, for which purpose fresh blood would be less suitable by reason of its clotting. He would probably have carried a small quantity in a bottle, together with the pocket slab and roller invented by Mr. Galton. It would thus be possible for him to put a drop on the slab, roll it out into a thin film and take a clean impression with his stamp. It must be remembered that these precautions were quite necessary, since he had to make a recognisable print at the first attempt. A failure and a second trial would have destroyed the accidental appearance, and might have aroused suspicion."

"You have made some enlarged photographs of the thumb-prints, have you not?"

"Yes. I have here two enlarged photographs, one of the 'Thumbograph' print and one of the red thumb-print. They both show the white mark very clearly and will assist comparison of the originals, in which the mark is plainly visible through a lens."

He handed the two photographs up to the judge, together with the 'Thumbograph,' the memorandum slip, and a powerful doublet lens with which to examine them.

The judge inspected the two original documents with the aid of the lens and compared them with the photographs, nodding approvingly as he made out the points of agreement. Then he passed them on to the jury and made an entry in his notes.

While this was going on my attention was attracted by Walter Hornby. An expression of terror and wild despair had settled on his face, which was ghastly in its pallor and bedewed with sweat. He looked furtively at Thorndyke and, as I noted the murderous hate in his eyes, I recalled our midnight adventure in John Street and the mysterious cigar.

Suddenly he rose to his feet, wiping his brow and steadying himself against the bench with a shaking hand; then he walked quietly to the door and went out. Apparently, I was not the only onlooker who had been interested in his doings, for, as the door swung to after him, Superintendent Miller rose from his seat and went out by the other door.

"Are you cross-examining this witness?" the judge inquired, glancing at Sir Hector Trumpler.

"No, my lord," was the reply.

"Are you calling any more witnesses, Mr. Anstey?"

"Only one, my lord," replied Anstey—"the prisoner, whom I shall put in the witness-box, as a matter of form, in order that he may make a statement on oath."

Reuben was accordingly conducted from the dock to the witness-box, and, having been sworn, made a solemn declaration of his innocence. A brief cross-examination followed, in which nothing was elicited, but that Reuben had spent the evening at his club and gone home to his rooms about half-past eleven and had let himself in with his latchkey. Sir Hector at length sat down; the prisoner was led back to the dock, and the Court settled itself to listen to the speeches of the counsel.

"My lord and gentlemen of the jury," Anstey commenced in his clear, mellow tones, "I do not propose to occupy your time with a long speech. The evidence that has been laid before you is at once so intelligible, so lucid, and so conclusive, that you will, no doubt, arrive at your verdict uninfluenced by any display of rhetoric either on my part or on the part of the learned counsel for the prosecution.

"Nevertheless, it is desirable to disentangle from the mass of evidence those facts which are really vital and crucial.

"Now the one fact which stands out and dominates the whole case is this: The prisoner's connection with this case rests solely upon the police theory of the infallibility of finger-prints. Apart from the evidence of the thumb-print there is not, and there never was, the faintest breath of suspicion against him. You have heard him described as a man of unsullied honour, as a man whose character is above reproach; a man who is trusted implicitly by those who have had dealings with him. And this character was not given by a casual stranger, but by one who has known him from childhood. His record is an unbroken record of honourable conduct; his life has been that of a clean-living, straightforward gentleman. And now he stands before you charged with a miserable, paltry theft; charged with having robbed that generous friend, the brother of his own father, the guardian of his childhood and the benefactor who has planned and striven for his well-being; charged, in short, gentlemen, with a crime which every circumstance connected with him and every trait of his known character renders utterly inconceivable. Now upon what grounds has this gentleman of irreproachable character been charged with this mean and sordid crime? Baldly stated, the grounds of the accusation are these: A certain learned and eminent man of science has made a statement, which the police have not merely accepted but have, in practice, extended beyond its original meaning. That statement is as follows: 'A complete, or nearly complete, accordance between two prints of a single finger … affords evidence requiring no corroboration, that the persons from whom they were made are the same.'

"That statement, gentlemen, is in the highest degree misleading, and ought not to have been made without due warning and qualification. So far is it from being true, in practice, that its exact contrary is the fact; the evidence of a finger-print, in the absence of corroboration, is absolutely worthless. Of all forms of forgery, the forgery of a finger-print is the easiest and most secure, as you have seen in this court to-day. Consider the character of the high-class forger—his skill, his ingenuity, his resource. Think of the forged banknotes, of which not only the engraving, the design and the signature, but even the very paper with its private watermarks, is imitated with a perfection that is at once the admiration and the despair of those who have to distinguish the true from the false; think of the forged cheque, in which actual perforations are filled up, of which portions are cut out bodily and replaced by indistinguishable patches; think of these, and then of a finger-print, of which any photo-engraver's apprentice can make you a forgery that the greatest experts cannot distinguish from the original, which any capable amateur can imitate beyond detection after a month's practice; and then ask yourselves if this is the kind of evidence on which, without any support or corroboration, a gentleman of honour and position should be dragged before a criminal court and charged with having committed a crime of the basest and most sordid type.