CHAPTER X
PERSONAL IDENTIFICATION
We shall speak in this chapter of the aid that finger prints can give to personal identification, supposing throughout that facilities exist for taking them well and cheaply, and that more or less practice in reading them has been acquired by many persons. A few introductory words will show this supposition to be reasonable. At the present moment any printer, and there are many printers in every town, would, at a small charge, blacken a slab and take the prints effectively, after being warned to use very little ink, as described in Chapter III. The occupation of finger printing would, however, fall more naturally into the hands of photographers, who, in addition to being found everywhere, are peculiarly well suited to it, for, taken as a class, they are naturally gifted with manual dexterity and mechanical ingenuity. Having secured good impressions, they could multiply them when necessary, and enlarge when desired, while the ticketing and preservation of the negatives would fall into their usual business routine. As they already occupy themselves with one means of identification, a second means of obtaining the same result is allied to their present work.
Were it the custom for persons about to travel to ask for prints of their fingers when they were photographed, a familiarity with the peculiarities of finger prints, and the methods of describing and classifying them, would become common. Wherever finger prints may be wanted for purposes of attestation and the like, the fact mentioned by Sir W. Herschel (p. 45) as to the readiness with which his native orderlies learnt to take them with the ink of his office stamp, must not be forgotten.
The remarks about to be made refer to identification generally, and are not affected by the fact that the complete process may or may not include the preliminary search of a catalogue; the two stages of search and of comparison will be treated separately towards the close of the chapter.
In civilised lands, honest citizens rarely need additional means of identification to their signatures, their photographs, and to personal introductions. The cases in which other evidence is wanted are chiefly connected with violent death through accident, murder, or suicide, which yield the constant and gruesome supply to the Morgue of Paris, and to corresponding institutions in other large towns, where the bodies of unknown persons are exposed for identification, often in vain. But when honest persons travel to distant countries where they have few or no friends, the need for a means of recognition is more frequently felt. The risk of death through accident or crime is increased, and the probability of subsequent identification diminished. There is a possibility not too remote to be disregarded, especially in times of war, of a harmless person being arrested by mistake for another man, and being in sore straits to give satisfactory proof of the error. A signature may be distrusted as a forgery. There is also some small chance, when he returns to his own country after a long absence, of finding difficulty in proving who he is. But in civilised lands and in peaceable times, the chief use of a sure means of identification is to benefit society by detecting rogues, rather than to establish the identity of men who are honest. Is this criminal an old offender? Is this new recruit a deserter? Is this professed pensioner personating a man who is dead? Is this upstart claimant to property the true heir, who was believed to have died in foreign lands?
In India and in many of our Colonies the absence of satisfactory means for identifying persons of other races is seriously felt. The natives are mostly unable to sign; their features are not readily distinguished by Europeans; and in too many cases they are characterised by a strange amount of litigiousness, wiliness, and unveracity. The experience of Sir W. Herschel, and the way in which he met these unfavourable conditions by the method of finger prints, has been briefly described in p. 27. Lately Major Ferris, of the Indian Staff Corps, happening to visit my laboratory during my absence, and knowing but little of what Sir W. Herschel had done, was greatly impressed by the possibilities of finger prints. After acquainting himself with the process, we discussed the subject together, and he very kindly gave me his views for insertion here. They are as follow, with a few trifling changes of words:--
"During a period of twenty-three years, eighteen of which have been passed in the Political Department of the Bombay Government, the great need of an official system of identification has been constantly forced on my mind.
"The uniformity in the colour of hair, eyes, and complexion of the Indian races renders identification far from easy, and the difficulty of recording the description of an individual, so that he may be afterwards recognised, is very great. Again, their hand-writing, whether it be in Persian or Devanagri letters, is devoid of character and gives but little help towards identification.
"The tenacity with which a native of India cleaves to his ancestral land, his innate desire to acquire more and more, and the obligation that accrues to him at birth of safeguarding that which has already been acquired, amounts to a religion, and passes the comprehension of the ordinary Western mind. This passion, or religion, coupled with a natural taste for litigation, brings annually into the Civil Courts an enormous number of suits affecting land. In a native State at one time under my political charge, the percentage of suits for the possession of land in which the title was disputed amounted to no less than 92, while in 83 per cent of these the writing by which the transfer of title purported to have been made, was repudiated by the former title-holder as fraudulent and not executed by him. When it is remembered that an enormous majority of the landholders whose titles come into court are absolutely illiterate, and that their execution of the documents is attested by a mark made by a third party, frequently, though not always apparently, interested in the transfer, it will be seen that there is a wide door open to fraud, whether by false repudiation or by criminal attempt at dispossession.
"It has frequently happened in my experience that a transfer of title or possession was repudiated; the person purporting to have executed the transfer asserting that he had no knowledge of it, and never authorised any one to write, sign, or present it for registration. This was met by a categorical statement on the part of the beneficiary and of the attesting witnesses, concerning the time, date, and circumstances of the execution and registration, that demolished the simple denial of the man whom it was sought to dispossess. Without going into the ethics of falsehood among Western and Eastern peoples, it would be impossible to explain how what is repugnant to the one as downright lying, is very frequently considered as no more than venial prevarication by the other. This, however, is too large a subject for present purposes, but the fact remains that perjury is perpetrated in Indian Courts to an extent unknown in the United Kingdom.
"The interests of landholders are partially safeguarded by the Act that requires all documents effecting the transfer of immovable property to be registered, but it could be explained, though not in the short space of this letter, how the provisions of the Act can be, and frequently are, fulfilled in the absence of the principal person, the executor.
"Enough has been said to show that if some simple but efficient means could be contrived to identify the person who has executed a bond, cases of fraud such as these would practically disappear from the judicial registers. Were the legislature to amend the Registration Act and require that the original document as well as the copy in the Registration Book should bear the imprint of one or more fingers of the parties to the deed, I have little hesitation in saying that not only would fraud be detected, but that in a short time the facility of that detection would act as a deterrent for the future. [This was precisely the experience of Sir W. Herschel.--F.G.] In the majority of cases, the mere question would be, Is the man A the same person as B, or is he not? and of that question the finger marks would give unerring proof. For example, to take the simplest case, A is sued for possession of some land, the title of which he is stated to have parted with to another for a consideration. The document and the Registration Book both bear the imprint of the index finger of the right hand of A. A repudiates, and a comparison shows that whereas the finger pattern of A is a whorl, the imprint on the document is a loop; consequently A did not execute it.
"In the identification of Government pensioners the finger print method would be very valuable. At one period, I had the payment of many hundreds of military pensioners. Personation was most difficult to detect in persons coming from a distance, who had no local acquaintances, and more especially where the claimants were women. The marks of identification noted in the pension roll were usually variations of:--"Hair black--Eyes brown--Complexion wheat colour--Marks of tattooing on fore-arm"--terms which are equally appropriate to a large number of the pensioners. The description was supplemented in some instances, where the pensioner had some distinguishing mark or scar, but such cases are considerably rarer than might be supposed, and in women the marks are not infrequently in such a position as to practically preclude comparison. Here also the imprint of one or more finger prints on the pension certificate, would be sufficient to settle any doubt as to identity.
"As a large number of persons pass through the Indian gaols not only while undergoing terms of imprisonment, but in default of payment of a fine, it could not but prove of value were the finger prints of one and all secured. They might assist in identifying persons who have formerly been convicted, of whom the local police have no knowledge, and who bear a name that may be the common property of half a hundred in any small town."
Whatever difficulty may be felt in the identification of Hindoos, is experienced in at least an equal degree in that of the Chinese residents in our Colonies and Settlements, who to European eyes are still more alike than the Hindoos, and in whose names there is still less variety. I have already referred (p. 26) to Mr. Tabor, of San Francisco, and his proposal in respect to the registration of the Chinese. Remarks showing the need of some satisfactory method of identifying them, have reached me from various sources. The _British North Borneo Herald_, August 1, 1888, that lies before me as I write, alludes to the difficulty of identifying coolies, either by photographs or measurements, as likely to become important in the early future of that country.
For purposes of registration, the method of printing to be employed, must be one that gives little trouble on the one hand, and yields the maximum of efficiency for that amount of trouble on the other. Sir W. Herschel impressed simultaneously the fore and middle fingers of the right hand. To impress simultaneously the fore, middle, and ring-fingers of the right hand ought, however, to be better, the trouble being no greater, while three prints are obviously more effective than two, especially for an off-hand comparison. Moreover, the patterns on the ring-finger are much more variable than those on the middle finger. Much as rolled impressions are to be preferred for minute and exhaustive comparisons, they would probably be inconvenient for purposes of registration or attestation. Each finger has to be rolled separately, and each separate rolling takes more time than a dab of all the fingers of one hand simultaneously. Now a dabbed impression of even two fingers is more useful for registration purposes than the rolled impression of one; much more is a dabbed impression of three, especially when the third is the variable ring-finger. Again, in a simultaneous impression, there is no doubt as to the sequence of the finger prints being correct, but there may be some occasional bungling when the fingers are printed separately.
* * * * *
For most criminal investigations, and for some other purposes also, the question is not the simple one just considered, namely, "Is A the same person, or a different person from B?" but the much more difficult problem of "Who is this unknown person X? Is his name contained in such and such a register?" We will now consider how this question may be answered.
Registers of criminals are kept in all civilised countries, but in France they are indexed according to the method of M. Alphonse Bertillon, which admits of an effective search being made through a large collection. We shall see how much the differentiating power of the French or of any other system of indexing might be increased by including finger prints in the register.
M. Bertillon has described his system in three pamphlets:--
(1) _Une application pratique de l'anthropometrie_, Extrait des Annales de Demographie Interne. Paris 1881. (2) _Les signalements anthropometriques_, Conference faite au Congres Penitentiare International de Rome, Nov. 22, 1885. (3) _Sur le fonctionnement du service des signalements_. All the above are published by Masson, 120 Boulevard St. Germain, Paris. To these must be added a very interesting but anonymous pamphlet, based on official documents, and which I have reason to know is authorised by M. Bertillon, namely, (4) _L'anthropometrie Judiciare en Paris, en 1889_: G. Stenheil, 2 Rue Casimir-Delavigne, Paris.
Besides these a substantial volume is forthcoming, which may give a satisfactory solution to some present uncertainties.
The scale on which the service is carried on, is very large. It was begun in 1883, and by the end of 1887 no less than 60,000 sets of measures were in hand, but thus far only about one half of the persons arrested in Paris were measured, owing to the insufficiency of the staff. Arrangements were then made for its further extension. There are from 100 to 150 prisoners sentenced each day by the Courts of Law in Paris to more than a few days' imprisonment, and every one of these is sent to the Depot for twenty-four hours. While there, they are now submitted to _Bertillonage_, a newly coined word that has already come into use. This is done in the forenoon, by three operators and three clerks; six officials in all. About half of the prisoners are old offenders, of whom a considerable proportion give their names correctly, as is rapidly verified by an alphabetically arranged catalogue of cards, each of which contains front and profile photographs, and measurements. The remainder are examined strictly; their bodily marks are recorded according to a terse system of a few letters, and they are variously measured. Each person occupies seven or eight minutes. They are then photographed. From sixty to seventy-five prisoners go through this complete process every forenoon. In the afternoon the officials are engaged in making numerous copies of each set of records, one of which is sent to Lyon, and another to Marseille, where there are similar establishments. They also classify the copies of records that are received from those towns and elsewhere in France, of which from seventy to one hundred arrive daily. Lastly, they search the Registers for duplicate sets of measures of those, whether in Paris or in the provinces, who were suspected of having given false names. The entire staff consists of ten persons. It is difficult to rightly interpret the figures given in the pamphlet (4) at pp. 22-24, as they appear to disagree, but as I understand them, 562 prisoners who gave false names in the year 1890 were recognised by _Bertillonage_, and only four other persons were otherwise discovered to have been convicted previously, who had escaped recognition by its means.
I had the pleasure of seeing the system in operation in Paris a few years ago, and was greatly impressed by the deftness of the measuring, and with the swiftness and success with which the assistants searched for the cards containing entries similar to the measures of the prisoner then under examination.
It is stated in the _Signalements_ (p. 12) that the basis of the classification are the four measurements (1) Head-length, (2) Head-breadth, (3) Middle-finger-length, (4) Foot-length, their constancy during adult life nearly always [as stated] holding good. Each of these four elements severally is considered as belonging to one or other of three equally numerous classes--small, medium, and large; consequently there are 3{4} or 81 principal headings, under some one of which the card of each prisoner is in the first instance sorted. Each of these primary headings is successively subdivided, on the same general principle of a three-fold classification, according to other measures that are more or less subject to uncertainties, namely, the height, the span, the cubit, the length and breadth of the ear, and the height of the bust. The eye-colour alone is subjected to seven divisions. The general result is (pp. 19, 22) that a total of twelve measures are employed, of which eleven are classed on the three-fold principle, and one on the seven-fold, giving a final result of 3{11} x 7, or more than a million possible combinations. M. Bertillon considers it by no means necessary to stop here, but in his chapter (p. 22) on the "Infinite Extension of the Classification," claims that the method may be indefinitely extended.
The success of the system is considered by many experts to be fully proved, notwithstanding many apparent objections, one of which is the difficulty due to transitional cases: a belief in its success has certainly obtained a firm hold upon the popular imagination in France. Its general acceptance elsewhere seems to have been delayed in part by a theoretical error in the published calculations of its efficiency: the measures of the limbs which are undoubtedly correlated being treated as independent, and in part by the absence of a sufficiently detailed account of the practical difficulties experienced in its employment. Thus in the _Application pratique_, p. 9: "We are embarrassed what to choose, the number of human measures which vary independently of each other being considerable." In the _Signalements_, p. 19: "It has been shown" (by assuming this independent variability) "that by seven measurements, 60,000 photographs can be separated into batches of less than ten in each." (By the way, even on that assumption, the result is somewhat exaggerated, the figures having been arrived at by successively taking the higher of the two nearest round values.) In short, the general tone of these two memoirs is one of enthusiastic belief in the method, based almost wholly, so far as is there shown, on questionable _theoretic_ grounds of efficiency.
To learn how far correlation interferes with the regularity of distribution, causing more entries to be made under some index-heads than others, as was the case with finger prints, I have classified on the Bertillon system, 500 sets of measures taken at my laboratory. It was not practicable to take more than three of the four primary measures, namely, the head-length, its breadth, and the middle-finger-length. The other measure, that of foot-length, is not made at my laboratory, as it would require the shoes to be taken off, which is inconvenient since persons of all ranks and both sexes are measured there; but this matters little for the purpose immediately in view. It should, however, be noted that the head-length and head-breadth have especial importance, being only slightly correlated, either together or with any other dimension of the body. Many a small man has a head that is large in one or both directions, while a small man rarely has a large foot, finger, or cubit, and conversely with respect to large men.
The following set of five measures of each of the 500 persons were then tabulated: (1) head-length; (2) head-breadth; (3) span; (4) body-height, that is the height of the top of the head from the seat on which the person sits; (5) middle-finger-length. The measurements were to the nearest tenth of an inch, but in cases of doubt, half-tenths were recorded in (1), (2), and (5). With this moderate minuteness of measurement, it was impossible so to divide the measures as to give better results than the following, which show that the numbers in the three classes are not as equal as desirable. But they nevertheless enable us to arrive at an approximate idea of the irregular character of the distribution.
TABLE XVI.
+-----------------------------------------------------------------------+ | | Medium |Nos. in the three classes respectively.| | Dimensions | measures in |---------------------------------------| | measured. | inches and | - | 0 | + | Total. | | | tenths. | below. | medium. | above. | | |----------------|--------------|--------|---------|---------|----------| |1. Head-length | 7.5 to 7.7 | 101 | 191 | 208 | 500 | |2. Head-breadth | 6.0 " 6.1 | 173 | 201 | 126 | 500 | |3. Span | 68.0 " 70.5 | 137 | 165 | 198 | 500 | |4. Body-height | 35.0 " 36.0 | 139 | 168 | 193 | 500 | |5. Middle-finger| 4.5 " 4.6 | 180 | 176 | 144 | 500 | +-----------------------------------------------------------------------+
The distribution of the measures is shown in Table XVII.
TABLE XVII.
_Distribution of 500 sets of measures into classes. Each set consists of five elements; each element is classed as + or above medium class; M, or mediocre; -, or below medium class._
(Total number of classes is 3{5} = 243.)
+----------------------------------------------------------------+ | +---- 3 Span. | | | | | | | | +--4 Body- | 1 Head-length, 2 Head-breadth. | | | | height.| | | | | | | | | | 5 Middle-|-----------------------------------------------| | | | | finger.| 1 2 1 2 1 2 | 1 2 1 2 1 2 | 1 2 1 2 1 2 | | | | | |---------------|---------------|---------------| | | | | | - - - M - + | M - M M M + | + - + M + + | |----------------|---------------|---------------|---------------| | - - - | 14 7 4 | 14 11 5 | 3 3 2 | | M | - 2 - | 2 4 1 | - 2 4 | | + | - - - | 1 - - | - - - | | | | | | | - M - | 5 2 2 | 7 4 2 | 1 4 3 | | M | - 2 - | 3 1 3 | 2 3 - | | + | - - - | - - - | - - 2 | | | | | | | - + - | 2 - - | 1 1 1 | - - 1 | | M | - 2 - | - - - | - 1 1 | | + | - - - | 1 - - | - 1 - | |----------------|---------------|---------------|---------------| | M - - | 4 - 1 | 3 4 3 | 1 2 2 | | M | 3 2 - | 3 2 3 | 2 4 - | | + | - - - | - 1 2 | - 1 - | | | | | | | M M - | 1 3 1 | 4 3 2 | 4 4 3 | | M | 5 3 - | 7 5 2 | 2 6 5 | | + | 2 1 1 | 1 1 - | 1 4 2 | | | | | | | M + - | 2 1 1 | 5 2 - | - 2 2 | | M | 2 2 - | 3 3 1 | 1 6 7 | | + | - - 1 | 2 - - | 3 2 2 | |----------------|---------------|---------------|---------------| | + - - | - - 1 | - 1 - | - - - | | M | 1 - - | 1 2 - | 1 3 - | | + | 1 2 - | 1 1 - | - - 2 | | | | | | | + M - | 1 - 1 | 3 2 - | - - 2 | | M | 2 - 1 | 1 4 - | 3 2 4 | | + | 2 1 - | 2 4 1 | 4 6 3 | | | | | | | + + - | 1 2 - | 1 - 1 | 1 2 2 | | M | - 1 - | 5 10 3 | 3 8 9 | | + | 2 2 2 | 11 10 3 | 9 24 19 | +----------------------------------------------------------------+
The frequency with which 1, 2, 3, 4, etc., sets were found to fall under the same index-heading, is shown in Table XVIII.
TABLE XVIII.
+----------------------------------------------------+ | No. of sets | | | | under same | Frequency of its | No. of entries. | | index-heading.| occurrence. | | |---------------|------------------|-----------------| | 0 | 83 | 0 | | 1 | 47 | 47 | | 2 | 47 | 94 | | 3 | 25 | 75 | | 4 | 16 | 64 | | 5 | 7 | 35 | | 6 | 3 | 18 | | 7 | 4 | 28 | | 8 | 1 | 8 | | 9 | 2 | 18 | | 10 | 2 | 20 | | 11 | 2 | 22 | | 14 | 2 | 28 | | 19 | 1 | 19 | | 24 | 1 | 24 | |----------------------------------------------------| | Total entries 500 | +----------------------------------------------------+
No example was found of 83, say of one-third, of the 243 possible combinations. In one case no less than 24 sets fell under the same head; in another case 19 did so, and there were two cases in which 14, 11, and 10 severally did the same. Thus, out of 500 sets (see the five bottom lines in the last column of the above table) no less than 113 sets fell into four classes, each of which included from 10 to 24 entries.
The 24 sets whose Index-number is + M, + + + admit of being easily subdivided and rapidly sorted by an expert, into smaller groups, paying regard to considerable differences only, in the head-length and head-breadth. After doing this, two comparatively large groups remain, with five cases in each, which require further analysis. They are as follow, the height and eye-colour being added in each case, and brackets being so placed as to indicate measures that do not differ to a sufficient amount to be surely distinguished. No two sets are alike throughout, some difference of considerable magnitude always occurring to distinguish them. Nos. 2 and 3 come closest together, and are distinguished by eye-colour alone.
TABLE XIX.
Five cases of Head-length 8.0, and Head-breadth 6.1.
Span. Body. Finger. Height. Eye-colour.
1. { 72.4 38.0 4.8 { 71.2 { br. grey 2. { 72.6 { 37.0 { 4.7 { 71.4 { br. grey 3. { 72.7 { 36.7 { 4.7 { 71.4 blue 4. 73.9 36.4 5.0 70.7 brown 5. 75.3 37.9 4.8 73.4 blue
Five cases of Head-length 7.8, and Head-breadth 6.0.
6. 70.8 37.8 { 4.7 { 70.0 brown 7. { 71.9 36.2 { 4.7 { 69.3 blue 8. { 72.4 { 37.2 { 4.7 { 68.4 brown 9. 74.8 { 37.8 5.0 73.1 blue 10. 79.9 { 37.3 5.3 75.6 blue grey
This is satisfactory. It shows that each one of the 500 sets may be distinguished from all the others by means of only seven elements; for if it is possible so to subdivide twenty-four entries that come under one index-heading, we may assume that we could do so in the other cases where the entries were fewer. The other measures that I possess--strength of grasp and breathing capacity--are closely correlated with stature and bulk, while eyesight and reaction-time are uncorrelated, but the latter are hardly suited to test the further application of the Bertillon method.
It would appear, from these and other data, that a purely anthropometric classification, irrespective of bodily marks and photographs, would enable an expert to deal with registers of considerable size.
Bearing in mind that mediocrities differ less from one another than members of either of the extreme classes, and would therefore be more difficult to distinguish, it seems probable that with comparatively few exceptions, _at least_ two thousand adults of the same sex might be individualised, merely by means of twelve careful measures, on the Bertillon system, making reasonable allowances for that small change of proportions that occurs after the lapse of a few years, and for inaccuracies of measurement. This estimate may be far below the truth, but more cannot, I think, be safely inferred from the above very limited experiment.
The system of registration adopted in the American army for tracing suspected deserters, was described in a memoir contributed to the "International Congress of Demography," held in London in 1891. The memoir has so far been only published in the _Abstracts of Papers_, p. 233 (Eyre and Spottiswoode). Its phraseology is unfortunately so curt as sometimes to be difficult to understand; it runs as follows:--
Personal identity as determined by scars and other body marks by Colonel Charles R. Greenleaf and Major Charles Smart, Medical Department, U.S. Army.
Desertions from United States army believed to greatly exceed deserters, owing to repeaters.
Detection of repeaters possible if all body marks of all recruits recorded, all deserters noted, and all recruits compared with previous deserters.
In like manner men discharged for cause excluded from re-entry.
Bertillon's anthropometric method insufficient before courts-martial, because possible inaccuracies in measurement, and because of allowable errors.
But identity acknowledged following coincident indelible marks, when height, age, and hair fairly correspond.
That is, Bertillon's collateral evidence is practically primary evidence for such purposes.
There is used for each man an outline figure card giving anterior and posterior surfaces, divided by dotted lines into regions.
These, showing each permanent mark, are filed alphabetically at the Surgeon-General's office, War Department.
As a man goes out for cause, or deserts, his card is placed in a separate file.
The cards of recruits are compared with the last-mentioned file.
To make this comparison, a register in two volumes is opened, one for light-eyed and one for dark-eyed men. Each is subdivided into a fair number of pages, according to height of entrants, and each page is ruled in columns for body regions. Tattooed and non-tattooed men of similar height and eyes are entered on opposite pages. Recruits without tattoos are not compared with deserters with tattoos; but recruits with tattoos are compared with both classes.
On the register S T B M, etc., are used as abbreviations for scar, tattoo, birth-mark, mole, etc.
One inch each side of recorded height allowed for variation or defective measurement.
When probability of identity appears, the original card is used for comparison.
Owing to obstacles in inaugurating new system, its practical working began with 1891, and, to include May 1891 [= 5 months, F.G.], out of sixty-two cases of suspected fraud sixty-one proved real.
There was some interesting discussion, both upon this memoir and on a verbal communication concerning the French method, that had been made by M. Jacques Bertillon the statistician, who is a brother of its originator. It appeared that there was room for doubt whether the anthropometric method had received a fair trial in America, the measurements being made by persons not specially trained, whereas in France the establishments, though small, are thoroughly efficient.
There are almost always moles or birth-marks, serving for identification, on the body of every one, and a record of these is, as already noted, an important though subsidiary part of the Bertillon system. Body-marks are noted in the English registers of criminals, and it is curious how large a proportion of these men are tattooed and scarred. How far the body-marks admit of being usefully charted on the American plan, it is difficult to say, the success of the method being largely dependent on the care with which they are recorded. The number of persons hitherto dealt with on the American plan appears not to be very large. As observations of this class require the person to be undressed, they are unsuitable for popular purposes of identification, but the marks have the merit of serving to identify at all ages, which the measurements of the limbs have not.
It seems strange that no register of this kind, so far as I know, takes account of the teeth. If a man, on being first registered, is deficient in certain teeth, they are sure to be absent when he is examined on a future occasion. He may, and probably will in the meantime, have lost others, but the fact of his being without specified teeth on the first occasion, excludes the possibility of his being afterwards mistaken for a man who still possesses them.
We will now separately summarise the results arrived at, in respect to the two processes that may both be needed in order to effect an identification.
First, as regards _search in an Index_.--Some sets of measures will give trouble, but the greater proportion can apparently be catalogued with so much certainty, that if a second set of measures of any individual be afterwards taken, no tedious search will be needed to hunt out the former set. Including the bodily marks and photographs, let us rate the Bertillon method as able to cope with a register of 20,000 adults of the same sex, with a small and definable, but as yet unknown, average dose of difficulty, which we will call _x_.
A catalogue of 500 sets of finger prints easily fulfils the same conditions. I could lay a fair claim to much more, but am content with this. Now the finger patterns have been shown to be so independent of other conditions that they cannot be notably, if at all, correlated with the bodily measurements or with any other feature, not the slightest trace of any relation between them having yet been found, as will be shown at p. 186, and more fully in Chapter XII. For instance, it would be totally impossible to fail to distinguish between the finger prints of twins, who in other respects appeared exactly alike. Finger prints may therefore be treated without the fear of any sensible error, as varying quite independently of the measures and records in the Bertillon system. Their inclusion would consequently increase its power fully five-hundred fold. Suppose one moderate dose of difficulty, _x_, is enough for dealing with the measurements, etc., of 20,000 adult persons of the same sex by the Bertillon method, and a similar dose of difficulty with the finger prints of 500 persons, then two such doses could deal with a register of 20,000 x 500, or 10,000,000.
We now proceed to consider the second and final process, namely, that of identification by _Comparison_. When the data concerning a suspected person are discovered to bear a general likeness to one of those already on the register, and a minute comparison shows their finger prints to agree in all or nearly all particulars, the evidence thereby afforded that they were made by the same person, far transcends in trustworthiness any other evidence that can ordinarily be obtained, and vastly exceeds all that can be derived from any number of ordinary anthropometric data. _By itself it is amply sufficient to convict._ _Bertillonage_ can rarely supply more than grounds for very strong suspicion: the method of finger prints affords certainty. It is easy, however, to understand that so long as the peculiarities of finger prints are not generally understood, a juryman would be cautious in accepting their evidence, but it is to be hoped that attention will now gradually become drawn to their marvellous virtues, and that after their value shall have been established in a few conspicuous cases, it will come to be popularly recognised.
Let us not forget two great and peculiar merits of finger prints; they are self-signatures, free from all possibility of faults in observation or of clerical error; and they apply throughout life.
An abstract of the remarks made by M. Herbette, Director of the Penitentiary Department of the Ministere de l'Interieur, France, at the International Penitentiary Congress at Rome, after the communication by M. Alphonse Bertillon had been read, may fitly follow.
"Proceeding to a more extended view of the subject and praising the successful efforts of M. Bertillon, M. Herbette pointed out how a verification of the physical personality, and of the identity of people of adult age, would fulfil requirements of modern society in an indisputable manner under very varied conditions.
"If it were a question, for instance, of giving to the inhabitants of a country, to the soldiers of an army, or to travellers proceeding to distant lands, notices or personal cards as recognisable signs, enabling them always to prove who they are; if it were a question of completing the obligatory records of civil life by perfectly sure indications, such as would prevent all error, or substitution of persons; if it were a question of recording the distinctive marks of an individual in documents, titles or contracts, where his identity requires to be established for his own interest, for that of third parties, or for that of the State,--there the anthropometric system of identification would find place.
"Should it be a question of a life certificate, of a life assurance, or of a proof of death, or should it be required to certify the identity of a person who was insane, severely wounded, or of a dead body that had been partly destroyed, or so disfigured as to be hardly recognisable from a sudden or violent death due to crime, accident, shipwreck, or battle--how great would be the advantage of being able to trace these characters, unchangeable as they are in each individual, infinitely variable as between one individual and another, indelible, at least in part, even in death.
"There is still more cause to be interested in this subject when it is a question of identifying persons who are living at a great distance, and after the lapse of a considerable time, when the physiognomy, the features, and the physical habits may have changed from natural or artificial causes, and to be able to identify them without taking a journey and without cost, by the simple exchange of a few lines or figures that may be sent from one country or continent to another, so as to give information in America as to who any particular man is, who has just arrived from France, and to certify whether a certain traveller found in Rome is the same person who was measured in Stockholm ten years before.
"In one word, to fix the human personality, to give to each human being an identity, an individuality that can be depended upon with certainty, lasting, unchangeable, always recognisable and easily adduced, this appears to be in the largest sense the aim of the new method.
"Consequently, it may be said that the extent of the problem, as well as the importance of its solution, far exceeds the limits of penitentiary work and the interest, which is however by no means inconsiderable, that penal action has excited amongst various nations. These are the motives for giving to the labours of M. Bertillon and to their practical utilisation the publicity they merit."
These full and clear remarks seem even more applicable to the method of finger prints than to that of anthropometry.