The Science of Fingerprints by United States. Federal Bureau of Investigation (books to read in a lifetime txt) 📕

Director
Federal Bureau of Investigation
U.S. Department of Justice
Washington 25, D.C.

Attention: Identification Division—Latent Fingerprint Section.

If the package contains glass jars it should be marked "Fragile" to insure careful handling in transit.

The package should be sent railway express, prepaid, or, where there is need for speed, by air express, prepaid. When they are received by the Identification Division, the specimens will undergo various treatments which may necessitate further cutting, scraping, etc. In all cases, regardless of condition, the specimens will be returned after examination.

All of the foregoing matter has dealt with instances in which it has been assumed that all ten fingers are available, or a sufficient number of the fingers of a deceased have been secured and impressions suitable for searching through the fingerprint files of the FBI have been recorded.

There will be cases, however, where only a few, or possibly only one, of the fingers has sufficient ridge detail for identification. In such instances a search through the FBI files would be impractical. This, however, does not preclude the possibility of making a positive identification by the use of the one finger. Though a search through the file is not possible, a comparison can be made with the fingerprints of individuals who it is thought the deceased may be or, in some instances, with the fingerprints of missing persons.

In this connection, where one or only a few fingers are forwarded to the FBI, the names of all possible victims should also be submitted. The fingerprints of those individuals, if available, will then be taken out of file and compared with the ridge detail on the finger of the deceased in an endeavor to establish a positive identification. Many such identifications have been effected.

In conjunction with the usual services afforded authorized law enforcement agencies, the services of an FBI fingerprint expert are also made available in those cases where expert testimony is necessary to establish the identity of the deceased through fingerprints, providing, of course, such an identification has been made.

Extreme caution should be exercised in the case of the chemicals previously mentioned in this article. Acetone, alcohol, benzine, and xylene are highly inflammable and should neither be used near open flames nor while the operator is smoking. The fumes given off by acetone, benzine, xylene, and formaldehyde are toxic and may cause sickness. They should be used in a well-ventilated room only. It is also suggested that the fingerprint examiner wear rubber gloves when using acetone, benzine, xylene, formaldehyde, potassium hydroxide, or sodium hydroxide. These chemicals will cause the skin to peel. Strong concentrations may cause burns.

In conclusion, it is pointed out that the procedures and techniques which have been described are those currently being used by the fingerprint experts of the FBI. These methods are fast and the results have been most satisfactory. This Bureau does not claim, however, that satisfactory results cannot be achieved through variations thereof or different methods.

For the information and assistance of officials who desire to establish a local fingerprint identification bureau, the following suggestions are being made to indicate the principal materials necessary to equip such a bureau:

For the purpose of taking fingerprints there should be a stand with a clamp for holding the fingerprint cards steady. This latter item is necessary to prevent smudging the prints. A tube of printer's ink is used. The ink is applied by a roller to a glass plate upon which the fingers are inked before being rolled on the cards. The complete equipment for the above process may be secured from a number of commercial sources or it can be made. Figure 408 depicts an inking stand.

Fig. 408

[Fig. 408]

It is suggested that the fingerprint card be white, light cardboard, 8 by 8 inches, slightly glazed. This size is convenient, as it allows all the space necessary for recording the classification of the prints and general descriptive information concerning the individual. In the event the new bureau desires to contribute copies of its fingerprints to the Federal Bureau of Investigation, the latter will, upon request, gladly furnish fingerprint cards for the purpose together with envelopes and instructions on how to take fingerprints. It is suggested that the new bureau design its cards similar to those furnished by the Federal Bureau of Investigation, as these have been designed after special study and have been found to be satisfactory over a long period of time. Figures 409 and 410 show the fingerprint side and reverse side of the criminal fingerprint card used by the Federal Bureau of Investigation.

Fig. 409

[Fig. 409]

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Fig. 410

[Fig. 410]

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In classifying and comparing fingerprints it is necessary to use a magnifying or fingerprint glass. Such instruments can be obtained from various commercial sources. Figure 411 shows the type of magnifying glass used by the Federal Bureau of Investigation.

Fig. 411

[Fig. 411]

The fingerprint cards should be filed according to fingerprint classification sequence in cabinets, preferably steel. It is further suggested that the cabinets be three drawers high, with each drawer divided into three rows for filing. Such cabinets or similar ones can be obtained from various commercial sources. Figure 412 shows the type of fingerprint cabinet used in the Federal Bureau of Investigation.

Fig. 412

[Fig. 412]

In order to facilitate the location of classification groups, it is suggested that guide cards be placed in the rows of fingerprint cards at frequent intervals. These guide cards should be slightly longer and heavier than the fingerprint cards and should have small tabs on the top to hold classification identifying symbols. Figure 413 shows the type of guide card used by the Federal Bureau of Investigation.

Fig. 413

[Fig. 413]

A practice which has been of the utmost benefit in the Federal Bureau of Investigation is as follows: When a fingerprint card is taken out of its regular file for any reason, a substitute card is put in its place, to remain until the return of the card. This substitute card, or "charge-out" card, is of a different color from the fingerprint card and slightly longer. On it are recorded the name, the classification formula, and peculiar characteristics, such as scars and peculiar pattern formations, appearing on the original card. By indicating the date and reason for charging out the original card, the Bureau is able to keep an accurate check on the whereabouts of all prints at all times. It is suggested that the local bureaus adopt a practice of this kind whenever a fingerprint card is drawn from the files and it is known that it may be out for a period of time longer than the remainder of the day on which it is drawn. Figure 414 shows the type of charge-out card used in the FBI.

Fig. 414

[Fig. 414]

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Each fingerprint card handled by the bureau should receive a fingerprint number and these numbers can be assigned in consecutive order.

As the bureau increases in size, it will be found a source of much convenience to have fingerprints of males and females kept in separate files.

There will be times when it may be necessary to locate an individual's fingerprints when no current fingerprints are available, but the name with a police number or the classification is known. In order to facilitate work of this nature, as well as to keep a complete record and check on each set of fingerprints, it is necessary that the files be indexed in a manner similar to that in which books in a library are indexed.

In this connection, for each fingerprint card there is prepared an index card. On this the name of the individual is placed, with all known aliases, the fingerprint classification formula, the police or arrest number, the date of arrest or other action. It is desirable, also, to have on this card such general information as age, height, weight and race. Figure 415 shows the front of a suggested type of 3- by 5-inch index card.

Fig. 415

[Fig. 415]

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Figure 416 shows the reverse side of the 3- by 5-inch index card. These are filed alphabetically in special cabinets. An index card also should be made for every alias which an individual has used. Figure 417 shows an electrically operated file cabinet in which the index cards are filed. It is suggested that the alias cards be of a different color from the one bearing the correct name, known as the "Master." Each alias card also should have typed on it the correct name of the individual, for purposes of reference and cross-checking. For convenience and accuracy these files, as in the fingerprint files, should also have suitable guide cards.

Fig. 416

[Fig. 416]

Fig. 417

[Fig. 417]

It is advisable to make use of charge-out cards when original index cards are drawn from the files. Figure 418 shows a charge-out card.

Fig. 418

[Fig. 418]

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To supplant the 3- by 5-inch index cards mentioned above, many law enforcement agencies have found it desirable to use a separate sheet, sometimes referred to as a "History Sheet" or "Information Sheet," containing the complete case history of the subject involved. These separate sheets can be filed by fingerprint number sequence and contain not only the data such as the known aliases, the fingerprint classification formula, the arrest number, and other essential items which are set out on the 3- by 5-inch cards as heretofore described, but also contain a concise summary of the subject's arrest history, particularly with reference to his criminal activities in the particular city. They may also contain a summarized case history with respect to each arrest or commitment, including such items as the date and place of arrest, complete home address, relatives, the essential facts concerning the prosecution of charges, and the ultimate disposition.

When an identification bureau receives prints of individuals on whom it already has prints, it is not practical to keep more than one set of prints per person in what may be called the active fingerprint file. In these instances the better print should be designated a "Master" print by having the word "Master" stamped thereon. It should be given a number, to be known as the master number, which number should also be placed on all other sets of prints which may be found to be identical with the "Master" print. The "Master" print is placed in the active files. The extra prints are placed together in a heavy folder with their master number stamped thereon. This jacket folder is then filed in a separate cabinet. Also, if copies of all information regarding an individual, photographs, and FBI transcript of record are kept in this folder, his complete record