●Mechanical operation●Temporary disabilities●Permanent disabilities●General
●Mechanical operation
●Temporary disabilities
●Permanent disabilities
●General
In order to take good fingerprints, the necessary equipment should be maintained in a neat and orderly manner at all times.
Poor impressions are usually caused by one of the following faults:
1. The use of poor, thin, or colored ink, resulting in impressions which are too light and faint, or in which the ink has run, obliterating the ridges. The best results will be obtained by using heavy black printer's ink, a paste which should not be thinned before using. This ink will dry quickly and will not blur or smear with handling.
2. Failure to clean thoroughly the inking apparatus and the fingers of foreign substances and perspiration, causing the appearance of false markings and the disappearance of characteristics. Windshield cleaner, gasoline, benzine, and alcohol are good cleansing agents, but any fluid may be used. In warm weather each finger should be wiped dry of perspiration before printing.
3. Failure to roll the fingers fully from one side to the other and to ink the whole area from tip to below the first fissure. The result of this is that the focal points of the impressions (the deltas or cores) do not appear. The whole finger surface from joint to tip and from side to side should appear.
4. The use of too much ink, obliterating or obscuring the ridges. If printer's ink is used, just a touch of the tube end to the inking plate will suffice for several sets of prints. It should be spread to a thin, even film by rolling.
5. Insufficient ink, resulting in ridges too light and faint to be counted or traced.
6. Allowing the fingers to slip or twist, resulting in smears, blurs, and false-appearing patterns. The fingers should be held lightly without too much pressure. The subject should be warned not to try to help but to remain passive.
The illustrations numbered366 through 377show the results of these faults and show also the same fingers taken in the proper manner.
A brief review of the problems of classifying and filing a fingerprint card in the FBI will help to clarify the FBI's policy concerning the processing of "bad" inked fingerprints.
The criminal fingerprint file contains the fingerprints of millions of individuals. The complete classification formula is used. To obtain it, each inked finger must show all the essential characteristics. Because of the immense volume of prints it has become necessary to extend the normal classification formula.
To illustrate this point:
dWdwcxCdwcO 32 W OOO 18I 32 W III
dWdwcxCdwcO 32 W OOO 18I 32 W III
In order to subdivide the 32 over 32 primary still further, the ridge count of the whorl of the right little finger is used to obtain a final classification. The extension above the normal classification formula indicates that each whorl is classified as to the type; namely, plain whorl (W), double loop (D), central pocket loop (C), and accidental (X). Accordingly, it is not enough for the FBI Identification Division to ascertain the general whorl pattern type, but the deltas and core must show in order to obtain the ridge tracing, the type of whorl, and also, in some instances, the ridge count. The complete WCDX extension is outlined inChapter VI.
Figures 366 to 377 are some examples of improperly and properly taken inked fingerprints.
Figs. 366-369
Figs. 370-373
Figs. 374-377
[Figs. 366-377]
An examination of figure 372 shows that it is a whorl. In order to classify the ridge tracing accurately, however, so that the fingerprint card can be placed in the correct classification, the left delta must show. The approximate ridge tracing for the whorl in figure 372 would beMeeting. An examination of the properly taken fingerprint in figure 373 indicates that the correct ridge tracing isInner. It follows that the pattern in figure 372 would not have been placed in the proper place in file.
The correct whorl tracing is needed to obtain the complete subsecondary and the major classifications.
It may be noted that both deltas are present in figure 374. This would enable the technical expert to ascertain the correct ridge tracing,Outer. In the core of the whorl, however, there is a heavy amount of ink which makes it impossible to determine the type of whorl with any degree of accuracy. If one were to hazard a guess, it would appear to be a plain whorl. Actually, the correct type of whorl, a double loop, is clearly visible in figure 375.
It can be ascertained that the pattern in figure 376 is a loop, but an accurate ridge count cannot be obtained because the left delta does notappear. The approximate ridge count of this loop is 14 to 16. This approximation is sufficient for a fingerprint expert to place this loop in the "O" group of any finger of the subsecondary. The correct ridge count of this loop is 19, and it appears in illustration 377. The approximate ridge count is not sufficient to place this print properly in the large files of the FBI because in certain general complete classification formulas the accurate ridge count is needed to obtain an extension. These extensions use a smaller grouping of ridge counts to form a valuation table, and in this way, differ from the larger grouping of ridge counts which form the basis of the subsecondary classification. These extensions are called the second subsecondary and the special loop extension and are outlined inchapter VI.
There are two additional points which illustrate the FBI's need for the delta, ridges, and core to show clearly in loops. The first point is set forth: the ridge count of the loop may be needed to obtain the key classification. The key classification is an actual ridge count, and no valuation table is used to obtain a subdivision. The key classification is used as an integral part of the fingerprint filing system. The second point is as follows: the ridge count may be needed to obtain the final classification. The final classification is an actual ridge count, and no valuation table is used to obtain a subdivision. The final classification is used as an integral part of the fingerprint filing system.
The following are just a few examples to illustrate the completeness of the classification formula used in the FBI fingerprint file:
These several examples should help to illustrate the FBI's extended classification formulas for classifying and filing fingerprints.The larger collection of fingerprints must of necessity call for a more detailed analysis of all fingerprint characteristic details. The closer examination to obtain further fingerprint subdivisions is dependent on ten legible inked impressions.
The identification officer will understand the problems of accurately classifying and filing fingerprint cards. He knows there is little value in placing a fingerprint card in the FBI's files with only an approximate or an inaccurate classification.
Every fingerprint card filed in the FBI's file is of value to the particular law enforcement agency which forwarded it, as well as to all other law enforcement agencies which rely on its being correctly classified and filed.
There are temporary disabilities affecting an individual's hand which are sometimes beyond the control of the identification officer. These can be fresh cuts, or wounds, bandaged fingers or finger, occupational (carpenters, bricklayers, etc.) blisters, and excessive perspiration. Children, whose ridges are small and fine, would also come under this heading. Extreme care should be exercised in fingerprinting the aforementioned.
An indication on the fingerprint card to the effect "fresh cut, bandaged" is not sufficient to file the fingerprint card. It is obvious that a fingerprint card bearing these notations cannot be properly classified and filed. The same situation would occur if there were a blister on an individual's finger. The blister temporarily disfigures the ridge detail. When an injury is temporary, the prints, if at all possible, should not be taken until after the injury has healed.
Occupational problems (bricklayers, carpenters, etc.) are definitely a challenge to the identification officer. In some instances, by means of softening agents (oils and creams), it is possible to obtain legible inked impressions. It is further suggested that in these cases a very small amount of ink should be used on the inking plate.
Excessive perspiration can be controlled to some extent by the identification officer. Excessive perspiration causes the inked impressions to be indistinct. It is suggested in these cases to wipe the finger with a cloth and then immediately ink the finger and roll it on the fingerprint card. This process should be followed with each finger. It is also suggested that possibly the fingers could be wiped with alcohol, benzine, or similar fluid which would act as a drying agent.
In all the above situations, if it is not possible to accurately classify and file the fingerprint card, the name appearing on the card will be searched in the alphabetical files and then returned to the law-enforcement agency.
Another phase involves permanent disabilities which can in most cases be controlled by the identification officer. These can be lack of fingers (born without), amputations, crippled fingers (bent, broken), deformities (webbed, extra fingers), and old age.
With respect to lack of fingers, it should be noted that some individuals are born without certain fingers. The notation "missing" is not satisfactory because it does not sufficiently explain the correct situation. It is suggested that "missing at birth" or some similar notation be made in the individual fingerprint block on the card. A proper notation concerning this situation will prevent the fingerprint card from being returned. Figures 378 and 379 illustrate temporary and permanent disabilities.
Figs. 378-379
[Figs. 378-379]
Concerning amputations, it is suggested that a proper notation to this effect appear in the individual fingerprint block or blocks. It is suggested that if a portion of the first joint of a finger is amputated, the finger should be inked and printed. A notation concerning this fact should be made on the fingerprint card in the individual fingerprint block.
In those cases where all of the fingers are amputated, the inked footprints should be obtained.
The handling of crippled fingers and certain deformities can be discussed in a group because they generally present the same problems. It is not sufficient in all cases to indicate "broken," "bent," "crippled." If the fingers are bent or crippled so that they are touching the palm and cannot be moved, a notation to this effect should be on the fingerprint card in the proper individual fingerprint block. However, it is believed that these extreme cases are rare. It is suggested that the special inking devices used for taking the prints of deceased individuals be used in taking inked impressions of bent or crippled fingers.
This equipment, which will be discussed more fully in the section on printing deceased persons, consists of spatula, small roller, and a curved holder for the individual finger block. Figure 380 shows the spatula, roller, and curved holder. It should be further noted in figure 380 that there are a strip of the entire hand of the fingerprint card and also individual finger blocks cut from the fingerprint card. Each of these types can be used in connection with the curved holder.
Fig. 380
[Fig. 380]
Each crippled finger is taken as a separate unit and then the finger block pasted on a fingerprint card. In figure 381, note the use of the spatula for applying the ink to a bent or crippled finger; and in figure 382, observe the use of the curved holder for taking the "rolled" impression of a bent or crippled finger.
Figs. 381-382
[Figs. 381-382]
Old age has been placed under permanent disability only for discussion purposes. The problem is not encountered frequently in taking the fingerprints of individuals who are arrested. The situation of crippled fingers due to old age may be met, and it can be handled as previously suggested. In most cases the problems arise because of the very faint ridges of theindividual. It is believed that in the majority of cases, legibly inked prints can be taken by using a very small amount of ink on the inking plate and by using little pressure in the rolling of the fingers.
If a subject has more than 10 fingers, as occasionally happens, the thumbs and the next 4 fingers to them should be printed, and any fingers left over should be printed on the other side of the card with a notation made to the effect that they are extra fingers. When a person with more than 10 fingers has an intentional amputation performed, it is invariably the extra finger on the little finger side which is amputated.
It also happens, not infrequently, that a subject will have two or more fingers webbed or grown together, as in figures 383 and 384, making it impossible to roll such fingers on the inside. Such fingers should be rolled, however, as completely as possible, and a notation made to the effect that they are joined.
Fig. 383
Fig. 384
[Figs. 383-384]
Split thumbs, i.e., thumbs having two nail joints, as in figure 385, are classified as if the joint toward the outside of the hand were not present. In other words the inner joint is used, and no consideration whatever is given to the outer joint.
Fig. 385
[Fig. 385]
These problems have dealt with the mechanical or operational processes. However, there are other problems dealing with the completing of the descriptive information. The fingerprint card may be returned because of the lack of information in the spaces provided, such as name, sex, race, height, weight, etc. Any discrepancies in this information may necessitate the return of the fingerprint card.
The success and value of the FBI's fingerprint files to all law enforcement agencies are dependent, in a large measure, on the legibly inked fingerprints taken by law enforcement agencies.
Figure 386 shows an enlarged portion of the bulb of a finger revealing the microscopic structure of the friction skin. The epidermis consists of two main layers, namely, the stratum corneum, which covers the surface, and the stratum mucosum, which is just beneath the covering surface. The stratum mucosum is folded under the surface so as to form ridgeswhich will run lengthwise and correspond to the surface ridges. However, these are twice as numerous since the deeper ridges which correspond to the middle of the surface ridges alternate with smaller ones which correspond to the furrows. The sweat pores run in single rows along the ridges and communicate through the sweat ducts with the coil sweat glands which are below the entire epidermis. The friction ridges result from the fusion in rows of separate epidermic elements, such as the dot shown on the left. Generally speaking, when an individual bruises or slightly cuts the outer layer or stratum corneum of the bulb of the finger, the ridges will not be permanently defaced. However, if a more serious injury is inflicted on the bulb of the finger, thereby damaging the stratum mucosum, the friction skin will heal, but not in its original formation. The serious injury will result in a permanent scar appearing on the bulb of the finger.
Fig. 386
[Fig. 386]
Each year new graves are opened in potter's fields all over the United States. Into many of them are placed the unknown dead—those who have lived anonymously or who, through accident or otherwise, lose their lives under such circumstances that identification seems impossible. In a majority of such cases, after the burial of the body, no single item or clue remains to effect subsequent identification. As a result, active investigation usually ceases and the cases are forgotten, unless, of course, it is definitely established that a murder has been committed.
Reliance is too often placed on visual inspection in establishing the identity of the deceased. This includes having the remains viewed by individuals seeking to locate a lost friend or relative. The body is often decomposed. If death was caused by burning, the victim may be unrecognizable. As a result of many fatal accidents the deceased is often mutilated, particularly about the face, so that visual identification is impossible. Yet, in many cases, the only attempt at identification is by having persons view the remains and the personal effects.
The recorded instances of erroneous visual identifications are numerous. In one case a body, burned beyond recognition, was identified by relatives as that of a 21-year-old man; yet fingerprints later proved that the corpse was that of a 55-year-old man.
Fingerprints have frequently been instrumental in establishing the correct identity of persons killed in airplane crashes and incorrectly "identified" by close relatives.
In one instance a woman found dead in a hotel room was "positively" identified by several close friends. The body was shipped to the father of the alleged deceased in another state where again it was "identified" by close friends. Burial followed. Approximately one month later the persons who had first identified the body as that of their friend were sitting in a tavern when the "dead" woman walked into the room. Authorities were immediately advised of the error; they in turn advised the authorities in the neighboring state of the erroneous identification and steps were taken immediately to rectify the mistake. After permission had been granted by the State Health Board to exhume the body of the dead woman, fingerprints were taken and copies were forwarded to the FBI Identification Division. The finger impressions were searched through the fingerprint files and the true identity of the deceased was established.
During a 12-month period, the FBI Identification Division received thefingerprints of 1,708 unknown dead. Of these, 1,298, or almost 76 percent, were identified. The remaining 410 were not identified simply because fingerprints of these individuals were not in the FBI files. It should be noted that in these 1,708 cases, it was possible to secure legible fingerprints of the deceased in the usual manner by inking the fingers in those instances in which decomposition had not injured the ridge detail.
Fig. 387
[Fig. 387]
In addition to the fingerprints of 1,708 unknown dead, the Identification Division received the fingers and/or the hands of 85 unknown dead individuals. In these cases, decomposition was so far advanced that it was not possible to secure inked fingerprints in the regular manner. Of these, 68 bodies, or 80 percent of the group, were identified. Of the 17 unidentified, the fingerprints of 14 were not in the FBI files. In three cases decomposition was so far advanced that all ridge detail had been destroyed.
In order to emphasize what can be accomplished, it is pointed out that in those cases in which hands and fingers were submitted, the time which elapsed from death until the specimens were received ranged from a week to 3 years. Incredible as it may seem, it has been possible to secure identifiable impressions 3 years after death.
These statistics of achievement in the field of identifying unknown dead re-emphasize the fact that in all cases involving the identification of a deceased person, fingerprints should be used as the medium for establishing a conclusive and positive identification.
Generally speaking, in the course of their work fingerprint operators find it necessary to take the impressions of three classes of deceased persons.
They are:
● Those who have died recently, in which cases the task is relatively simple.● Those dead for a longer period, in which cases difficulty is experienced due to pronounced stiffening of the fingers, the early stages of decomposition, or both.● Those cases in which extreme difficulty is encountered because of maceration, desiccation, or advanced decay of the skin.
● Those who have died recently, in which cases the task is relatively simple.
● Those dead for a longer period, in which cases difficulty is experienced due to pronounced stiffening of the fingers, the early stages of decomposition, or both.
● Those cases in which extreme difficulty is encountered because of maceration, desiccation, or advanced decay of the skin.
These problems will be considered separately.
1. Fingerprinting the Newly Dead.
When the fingers are flexible it is often possible to secure inked fingerprint impressions of a deceased person through the regular inking process on a standard fingerprint card. Experience has proved that this task can be made easier if the deceased is laid face down and palms down on a table (fig. 388).
Fig. 388
[Fig. 388]
In all cases where inked impressions are to be made, care should be exercised to see that the fingers are clean and dry before inking. If necessary, wash the digits with soap and water and dry thoroughly.
In the event difficulty is encountered in trying to procure fingerprints by the regular method, it may prove more convenient to cut the 10 "squares" numbered for the rolled impressions from a fingerprint card. After the finger is inked, the square is rolled around the finger without letting it slip. Extreme caution should be exercised to see that each square bears the correct fingerprint impression. After all the inked impressions are properly taken, the ten squares bearing the impressions are pasted or stapled to a standard fingerprint card in their proper positions, i.e., right thumb, right index, right middle, etc. Whenever possible the "plain" or "simultaneous" impressions should also be taken.
In some cases it will be found necessary to obtain or improvise a tool similar to a broad-bladed putty knife or spatula to be used as an inking instrument. The ink is rolled evenly and thinly on the knife or spatula and applied to the finger by passing the inked knife or spatula around it. The tool, of course, replaces the usual glass inking slab or plate, the use of which is extremely difficult or awkward when printing a deceased person.
2. Fingerprinting the Dead, Where Stiffening of the Fingers and/or Early Decomposition Are Present.
This second group consists of cases in which the hands of the deceased are clenched, or the finger tips are wrinkled, or decomposition has begun, and/or where there are combinations of these three conditions. Cases of this sort may necessitate cutting off the skin. Legal authority is necessary before cutting a corpse. Such authority may be granted by state law or by an official having authority to grant such a right.
In cases where rigor mortis (stiffening of the muscles) has set in and the fingers are tightly clenched, the fingers may be forcibly straightened by "breaking the rigor." This is done by holding the hand of the deceased person firmly with one hand, grasping the finger to be straightened with the four fingers of the other hand and placing the thumb, which is used as a lever, on the knuckle of the finger and forcing it straight (fig. 389). The inking tool and "squares," as previously explained, are then used to secure the fingerprint.
Fig. 389
[Fig. 389]
In the event the rigor cannot be completely overcome, it will be most helpful to improvise or secure a spoon-shaped tool for holding the cut squares or cut strips while printing the fingers, similar to the tool mentionedbriefly in the discussion of crippled fingers. This tool, somewhat resembling a gouge without the sharp edge, should have a handle, a concave end, and a frame or clamp to hold the cardboard squares or strips. In Figure 390, one type of tool is illustrated. This tool eliminates the necessity of rolling the deceased's finger, since the "square" assumes the concave shape of the tool, and the gentle pressure applied to the inked finger when it is brought in contact with the square results in a "rolled" impression without actually rolling the finger.
Fig. 390
[Fig. 390]
Another problem encountered in this second group includes cases in which the tips of the fingers are fairly pliable and intact, yet due to the presence of wrinkles in the skin, complete impressions cannot be obtained. This condition can be corrected by the injection of a tissue builder, procurable from a dealer in undertaker's supplies. If this is not available, glycerin or water may be used.
The method is simple. Injection of the tissue builder, glycerin, or water, is accomplished by the use of a hypodermic syringe. The hypodermic needle is injected at the joint of the finger up into the tip of the finger, care being used to keep the needle below the skin surface (fig. 391). The solution is injected until the finger "bulbs" are rounded out, after which they are inked and printed.
Fig. 391
[Fig. 391]
Occasionally, in stubborn cases, entry of the needle at the joint and injection of the fluid will not completely fill the finger bulb. It may be necessary, therefore, to inject the fluid at other points of the finger such as the extreme tip or sides, until suitable results are achieved (fig. 392). The tissue builder has a distinct advantage over glycerin or water, inasmuch as the builder hardens after a short time and is not lost, whereas glycerin and water sometimes seep out when pressure is applied in printing. To offset seepage at the point where the hypodermic needle is injected, whenever possible, tie a piece of string tightly around the finger just above the point of entry of the needle.
Fig. 392
[Fig. 392]
When the tissue builder is purchased, a solvent for cleaning the hypodermic syringe and needle should be acquired, inasmuch as the builder will harden in the syringe and needle.
Those cases in which decomposition in its early stage is present belong in this group also. Frequently, the outer layer of skin has begun to peel from the fingers. A careful examination should be made to determine if the peeling skin is intact or if a part of it has been lost. If the skin is in one piece, an effort should be made to secure prints just as though it were attached normally to the finger. Or, if it is deemed advisable, the skin may be peeled off in one piece, placed over the finger of the operator, and inked and printed as though it were his own finger.
Occasionally the first layer of skin is missing. There remains the dermis or second layer of skin which is also of value for identification purposes. This second layer would be dealt with as though it were the outside skin, using the techniques described above. The ridge detail of the second layer of skin is less pronounced than that of the outer skin, however, and more attention and care are needed in order to obtain suitable impressions.
So far this discussion has dealt with the taking of impressions of fingers when the flesh is fairly firm and the ridge detail intact. A different problem arises when the fingers are in various stages of decay. The techniques of treating the fingers in such cases vary greatly, depending upon the condition of the fingers with respect to decomposition, desiccation, or maceration.
3. Fingerprinting the Dead in Difficult Cases.
In cases involving badly decomposed bodies the first thing to do is to examine the fingers to see if all are present. If they are not, an effort should be made to determine whether the missing finger or fingers or even a hand was amputated during the person's lifetime, or whether the loss was due to other causes such as destruction by animal or marine life. Deductions from this examination should be noted on the fingerprint record. This point is made in view of the fact that in the fingerprint files of the FBI and some police departments, the fingerprint cards reflecting amputations are filed separately. Noting amputations may lessen to a great extent a search through the fingerprint files.
In making the initial examination, attention should be given to the removal of dirt, silt, grease and other foreign matter from the fingers. Soap and water are good cleansing agents. So is xylene, a chemical which will readily clean grease and fatty matter from the fingers. Good results can be achieved by utilizing a child's soft-bristled toothbrush in cases where the skin is fairly firm. The brushing should be done lightly and the strokes should follow the ridge design in order to clean not only the ridges but the depressions as well. In the event that the skin is not firm enough to use the toothbrush, a cotton swab may be used. The fingers should be wiped very lightly with either soap and water or xylene, always following the ridge contours.
At this point the fingers are again examined to determine the conditionthey are in, based upon the circumstances in which the body was found. Study and actual experience have shown that there are three general types of conditions to be considered: Decomposition or putrefaction, prevalent in bodies found in brush or buried in earth; desiccation or mummification (that is, dried out), noted in bodies which have been found in the open (ridge detail not in contact with the ground) in dry protected places, or bodies subjected to severe heat; and the group involving maceration (water soaking), which ordinarily results from being immersed in water.
The degree of decomposition, desiccation, or maceration varies from a comparatively early stage to an extremely advanced stage. Accordingly, each case must be considered individually. For example, what is done successfully in one case of desiccation may not show favorable results in another. Hence, the techniques outlined below point out generally what can be done, and has been done, with success.
When a body is found, the hands usually will be tightly clenched. The first problem will be to straighten the fingers. If rigor mortis has set in and an effort to straighten the fingers as previously explained fails, the difficulty can be overcome easily. Using a scalpel, make a deep cut at the second joint on the inner side of each of the four fingers. They can now be straightened with the application of force (fig. 393). The thumb, if it is cramped or bent, can generally be straightened by making a deep cut between the thumb and the index finger. These incisions are made for the obvious purpose of examining the fingers to determine if there is any ridge detail. Before this fact can be definitely ascertained it may be necessary to cleanse the pattern areas with soap and water or xylene, as previously explained.
Fig. 393
[Fig. 393]
If the case is one involving decomposition, the operator is confronted with the problem of dealing with flesh which is rotted or putrefied. The flesh may be soft or flabby and very fragile. If this is so, an examination is made of the finger tips to see if the outer skin is present. If the outer skin is present and intact, it may be possible, using extreme care, to ink and print in the regular manner. Sometimes, the outer skin, although present, will be too soft and fragile to ink and roll in the regular way. In such cases, when the ridge detail is discernible, the skin, if it is easily removed from the finger, or the finger itself may be cut off at the second joint and placed in a 10- to 15-percent solution of formaldehyde for approximately an hour to harden it. Skin placed in a formaldehyde solution usually turns a grayish white and becomes firm. However, it willbe brittle and may split if not handled carefully. The skin is placed in the solution only until it hardens sufficiently, after which it is removed and carefully wiped dry with a piece of cloth. Then the skin, placed over the operator's own thumb or index finger and held in place by his other hand, is inked and rolled as though the operator were printing his own finger. If a legible print is not obtainable in this manner, the operator should examine the underside of the skin.
In many instances, where the ridge detail on the outer surface has been destroyed or is not discernible, the ridge detail is clearly visible on the underside (fig. 394). If this is the case, the skin is inverted (turned inside out) very carefully to prevent splitting or breaking and then is inked and printed in the usual way. It must be borne in mind, however, that when the underside of the skin is printed the resulting impression will be in reverse color and position; that is, the ink is actually adhering to what would be furrows of the pattern when viewed from the proper or outer side. If it is deemed inadvisable to try to invert or turn the skin inside out for fear of damaging it, a photograph of the inner ridge detail is made and the negative is printed to give an "as is" position photograph for proper classification and comparison purposes. In order to secure good photographs of the ridge detail it may be advisable to trim the skin, flatten it out between two pieces of glass, and photograph it in that position (fig. 395).
Fig. 394
Fig. 395
[Figs. 394-395]
When the entire finger is placed in the solution during the hardening process, the skin, in absorbing the formalin solution, may swell and comeloose from the finger. Should this occur, the skin must be removed carefully and the procedure outlined above followed. If, however, the skin still adheres to the finger and is not too wrinkled, ink is applied and prints made. Should the skin be too wrinkled to secure a satisfactory impression, consideration is given to the injection of the tissue builder under the skin as previously mentioned, in order to distend the pattern area. If successful, the finger is inked and printed. This, of course, can be done only when the skin is intact.
Should part of the skin be destroyed to the extent that tissue builder cannot be injected effectively, while examination discloses that the pattern area is present but wrinkled, cut off the entire pattern area from the joint to the tip of the finger (fig. 396). Care must be exercised to insure getting the complete fingerprint pattern as well as cutting deep enough to avoid injury to the skin.
Fig. 396
[Fig. 396]
After excision, the flesh is carefully and meticulously removed from the inside by scraping, cutting, and trimming until only the skin remains, or until the specimen is so thin it can be flattened out to remove most of the wrinkles. If the skin is fairly pliable, the operator should attempt to place it over one of his own fingers and try several prints. If the prints secured are not suitable, the piece of skin (exert care to avoid breaking or splitting) is flattened out between two pieces of glass and photographed (figs. 397, 398, 399).
Figs. 397-399
[Figs. 397-399]
The foregoing outline covers the procedures followed in cases involving decomposition in which the outer skin is still present. In many instances of decomposition the outer skin has been destroyed or is in such a condition as to be of no value. It must be emphasized again that the second layer of skin possesses the same ridge detail as the outer layer and this, though finer and less pronounced, is just as effective for identification purposes.
If, from examination, it is apparent that the outer layer of skin is missing and the second layer is intact, the finger should be cleansed, dried, inked, and printed in the usual manner. If the specimen is wrinkled but pliable it may be possible to inject tissue builder, as previously mentioned, to round out the finger, then ink and print it.
Occasionally, some of the outer skin is still attached but is of no value. This skin should be removed by carefully picking or prying it off with a scalpel in such a manner as not to destroy or injure the ridge detail of the second layer. After the outer fragments have been removed, the second layer is cleaned, inked, and printed. In the event the resultant impressions are not suitable for classification and identification purposes, the most likely reason for it is that the ridge detail is too fine to print even though there are few if any wrinkles in it. If this is the case, the finger should be cut off at the second joint and photographed. Should wrinkles which cannot be removed by injecting tissue builder, and which also preclude the taking of suitable photographs, be present, the pattern area is cut off with a scalpel from the first joint to the tip. The flesh is then cut and scraped out as previously described, until the specimen is thin enough to flatten out between two pieces of glass which may be held together by scotch tape. The skin is then photographed.
Occasionally, even after the flattening process it will be noted in the ground glass of the camera that the skin may be seen plainly but the ridge detail is very poor. This difficulty may be due to the poor contrast of the ridges and furrows when using direct lighting. If so, it can be overcome by scraping the skin to transparency and then photographing it by transmitted light (i.e., passing light through the skin). Sometimes, due to the condition of the skin, even though it is tissue thin, it will not be transparent. This can be overcome by soaking the skin in xylene for a few minutes and then photographing it by transmitted light while it is still impregnated with the xylene. If the substance dries too fast to permit proper photographing, the skin should be photographed while immersed in the xylene. (See subtopic of this chapter pertaining to "general photography.") Of course, after the skin has been photographed the negative should be printed to give a reverse position so that the print will be comparable with inked impressions on fingerprint cards.
The problem confronting the fingerprint examiner in treating fingers which are desiccated or dried and shriveled is that of distending and softening the skin. Desiccated fingers are generally found to have the outer layer of skin intact and the ridge detail fairly clear. However, due to the shrinking, numerous wrinkles will be present, and as the drying process continues the skin and flesh harden until the fingers become almost as hard as stone.
It is sometimes possible to distend or swell the flesh by utilizing a 1- to 3-percent solution of sodium hydroxide or potassium hydroxide, sometimes referred to as caustic potash. As a matter of caution, this process should be tried with one finger before using it for the remainingfingers. This point of caution is made because of the reaction of the potassium or sodium hydroxide, which is actually one of destruction. While absorption and swelling of the flesh occur, the disintegrating action of the fluid may result in total destruction of the flesh.
The finger to be distended is cut from the hand at the second joint and placed in the hydroxide. When it has resumed its normal size by the absorption of the solution, it is inked and printed. There is no set time for this process. The procedure may require a few hours or as much as several days until suitable results are obtained.
After the finger has been in the solution for about 30 minutes, it should be removed and examined in order to note the extent of the swelling and the reaction of the flesh to the solution. If no material change is noted, the finger is returned to the solution. A close watch is maintained and the finger is examined from time to time.
The solution may cause thin layers of skin to peel from the finger. Should this occur, the loose skin is carefully scraped off and the finger rinsed in water for a few minutes. It is then returned to the hydroxide for continuation of the process.
If, during the course of an inspection, it is seen that the flesh is becoming too soft, the finger should be placed in a 1- to 3-percent solution of formaldehyde or alcohol for several minutes in order to harden it.
If, after several hours in the hydroxide, the finger has not reached its normal size, it should be placed in water for an hour or two. This has a tendency to hasten the swelling. When the finger is removed, it will be noted that a film has coated the surface. This coating is carefully scraped off and the finger is replaced in the hydroxide solution for an hour or so, again scraped if coated, soaked in clean water, etc. This process of alternating from solution to water, scraping, and replacing in hydroxide is continued until desirable results are obtained. The finger is then inked and printed.
The above process will so saturate the finger with solution that it may be too wet to print properly. Accordingly, the finger may be dipped into acetone for several seconds, removed, and be permitted to dry, after which it is inked and printed.
The complete process may take from several hours to as much as 10 days to secure suitable results. If the final results of the above procedure are satisfactory with the one finger being tested, the remaining fingers are given the same treatment. Care must be taken to identify each finger properly as to right index, right middle, etc., to avoid any mixup.
In the event that the reaction of the solution on the first finger treated is not satisfactory and the operator feels that it would be futile to continue the process, the finger should be removed from the solution immediately, washed carefully in water, and placed in formaldehyde to harden sufficiently for it to be handled without causing injury to the ridges. Thepattern area is cut off in such a manner that sufficient surrounding surface permits the skin to be trimmed. Then from the cut side the skin is carefully scraped and cut to remove the excess flesh. While the cutting and scraping are being done, from time to time the skin should be soaked in xylene and massaged for purposes of softening to remove wrinkles. When the skin is thin enough and sufficiently pliable, the operator places the skin on his own finger, inks and prints it in the usual manner.
If the results are satisfactory, the same procedure is followed with the remaining fingers. In the event the resultant inked prints are not suitable, the skin should be scraped until it is sufficiently thin to be flattened between two pieces of glass and photographed.
Here again it is pointed out that should there be a poor contrast between the ridges and furrows when using direct lighting, the skin is scraped as thin as possible without tearing and it is then photographed by transmitted light.
There are also included, as cases of desiccation, bodies which have been burned or subjected to severe heat. Often there are cases where the skin has become loose but is hard and crisp, or where the finger has been severely burned and is reduced almost to carbon, yet is firm. In these instances the ridge detail usually has not been destroyed.
When a body which has been severely burned is located, the problems of identification should be anticipated. Accordingly, before the body is removed, a careful examination of the fingers should be made in order to determine if the removal would, in any way, cause damage to the fingers. Should it be felt that because of the condition of the body removal would cause injury to the ridge detail, securing of fingerprints at the scene, or possibly the cutting off of the hands or fingers to avoid destruction of the skin, should be considered. An examination of the fingers may disclose that the outer skin is hardened and is partially loosened from the flesh. It is sometimes possible, by twisting back and forth, to remove this outer skin intact. If this is done, the operator may place the skin on his own finger, ink and print in the usual way.
If the skin is intact on the finger and is not wrinkled, of course there is no problem and the usual method is employed to secure impressions.
Should wrinkles be present and the skin pliable, tissue builder is injected into the bulbs, which are then inked and printed.
In the event the wrinkles cannot be removed in this fashion, the pattern area is cut off and the excess flesh scraped out as before. While the scraping and cutting are being accomplished, the skin should be soaked and massaged in xylene to soften. The skin is then placed on the operator's finger, inked and printed. Should prints made in this manner be unsatisfactory, the next recourse is photography.
In some instances the fingers of burned bodies will be charred. Such cases require very careful handling as there is a probability of destroyingor disturbing the ridge detail through mistreatment. In these instances the procedure is determined by the degree of charring. In extreme cases the only method of recording is by photographing, using side lighting to secure the proper contrast of ridges and depressions. Obviously, no attempt should be made to ink and roll as the pressure necessary to secure the prints would cause the skin to crumble.
In instances where the charring has not reached the extreme stage the procedures previously set forth should be applied; that is, treatment of the skin by cleaning, softening, inking and printing, or, finally, by photographing (fig. 400).
Fig. 400
[Fig. 400]
The third and final type of case which may confront the identification officer concerns the problem of maceration, that is, long immersion of the fingers in water.
One of the cardinal rules for securing legible impressions is that the fingers must be dry. Accordingly, in these cases it becomes a matter of drying the fingers in addition to contending with other difficulties. Usually the skin on the fingers absorbs water, swells and loosens from the flesh within a few hours after immersion.
If an examination discloses the skin to be water-soaked, wrinkled and pliable, but intact, the first step is to cleanse the skin carefully as previously described. Next, wipe the fingertip with alcohol, benzine or acetone, waiting a few seconds for it to dry. The skin is pulled or drawn tightacross the pattern area so that a large wrinkle is formed on the back of the finger, then the bulb is inked and printed.
If the skin is broken and hanging loose, but its pattern area is intact, it should be removed from the finger, cleansed and placed in alcohol or benzine (not acetone) for about a minute, then stretched carefully over the operator's finger so as to remove any wrinkles. It may then be printed.
Sometimes the skin is intact on the finger but so wrinkled and hard that it is not possible to draw it tight for inking. In this case it may be advisable to inject tissue builder to round out the bulbs for inking and printing. Should this fail, the ridge detail is photographed on the finger; or the skin is cut off, flattened between two pieces of glass and then photographed. Here, again, it must be pointed out that when the ridge detail does not show on the surface of the outer skin the underside should be examined, for many times the detail can be seen clearly. Should this be true, of course, the underside is photographed.
In cases where it is noted that the outer skin is gone and the finger is not saturated with water, it is possible to dry the surface sufficiently for inking and printing purposes by rolling the finger on a blotter. If this fails, the finger is wiped off with a piece of cloth which has been saturated with alcohol, benzine or acetone, after which it may be inked and printed.
In many instances it will be found that the outer skin is gone and the fingers themselves are saturated with water. A quick method of drying out the fingers is to place them in full strength acetone for approximately 30 minutes. The fingers are then placed in xylene for about an hour or until the xylene has overcome the reaction of the acetone. After removal from the xylene the fingers should be placed on a blotter until the surface of the fingers appears dry. They are then ready to be inked and printed.
It will be noted in this procedure that when the fingers are removed from the acetone they dry and harden in a matter of seconds. The purpose of the xylene is to resoften the fingers. After this treatment, should the resulting inked impressions be unsuitable for classification purposes, the ridge detail should be photographed.
The use of X-ray photographs (radiography) has been advocated by some for purposes of recording the ridge details in decomposed, desiccated, or macerated cases. Briefly, the procedure involves the covering of the fingers with heavy salts such as bismuth or lead carbonate, in a thin, even film over the pattern area and then, by the use of the X-ray, reproducing theridge detail. This procedure necessitates the use of X-ray equipment and a technician skilled in making radiographs. It is, therefore, an expensive operation. The results of the radiograph in no way compensate for the expense, time, and skill required inasmuch as in those cases where many wrinkles and creases appear in the fingers, especially desiccated specimens, the results have been very poor. In instances where there are no wrinkles or only a few, and where the creases are not too deep, the ridge detail is reproduced very well in the radiograph. In these cases, however, it is usually possible to secure impressions by inking and rolling in the regular way or, should this fail, ordinary photography will certainly give satisfactory results. For economical and practical purposes the use of the X-ray is not recommended.
In the foregoing instances in which it has been impossible to obtain suitable inked impressions it will be noted that the last resort has always been photography. In all probability in advanced cases of decomposition, desiccation, and maceration it may not be possible to secure inked impressions which can be properly classified. Hence, it will be necessary to photograph the ridge detail. Accordingly, there are outlined below several methods of photographing the ridges which have been used with success.
In photographing the ridge detail on fingers it has been determined to be most practicable to photograph the finger natural, or 1/1, size inasmuch as comparisons will usually be made with inked impressions which are natural size. Any camera built or adjusted to taking 1/1 size pictures, and with which the lighting may be arranged to best advantage, may be used.
There is a wide choice of film which can be used for this purpose. The so-called soft films are all good for photographing ridge detail on fingers. Process film is not recommended inasmuch as the film presents too much of a contrast. Consequently, if it is used, some of the ridge detail will be lost, especially if wrinkles are present in the skin.
Lighting is accomplished by the use of gooseneck lamps, floodlights, or a spotlight. If a fingerprint camera is used, its lights may be sufficient.
The manner of lighting may be by direct light, side light, transmitted light or reflected light, depending upon the prevailing condition of the finger or skin.
Direct light is used in those cases in which the ridge detail is fairly clear and there are no wrinkles present; or, if wrinkles are present, they are not deep enough to interfere with photographing the ridges.
Side lighting is used when there are no wrinkles of any consequence and the ridge detail is clear but because of discoloration the ridgesare not readily seen in the ground glass as there is lack of contrast between ridges and depressions. Accordingly, the lights, instead of being focused directly on the skin or finger, are placed to the side of the object so that the light is directed across the skin or finger, thus highlighting the ridges and shading the depressions.
In side lighting, two lights may be used. Better results are often obtained, however, by using only one light, such as a spotlight, the beam of which can be controlled to best advantage.
Transmitted light is used in cases in which the skin has peeled off or in which the dermis has been removed, cut, and scraped thin so that light will go through. The prepared skin is placed between two pieces of glass pressed together in order to flatten the skin or dermis and remove creases. By trimming some of the surplus skin or dermis, especially at the top, it may be more easily flattened. After the glass is properly mounted in front of the camera, the lights are placed behind it and light is directed through the skin. The ridge detail is brought into focus on the ground glass. Before the picture is actually taken it is suggested that the ground glass be checked by first using one light and then two lights to see which is more effective.
There will be instances in which the second layer of skin, cut and scraped thin enough to flatten out, fails when dry to have a sufficient contrast between ridges and depressions for purposes of photographing. The same piece of skin when soaked in xylene will show a marked contrast, which it loses on drying. This difficulty is overcome by photographing the skin while in solution, which can be done by placing the skin in a test tube or a small bottle of a size to keep the skin upright and the ridges toward the camera. The test tube or bottle is then filled with xylene.
If the skin is sufficiently thin, transmitted light may be used. Should it be found, however, that transmitted light is not effective, then direct light may be tried and the results checked in the ground glass (fig. 401).
Fig. 401
[Fig. 401]
When photographing a small curved surface such as a test tube, direct lighting will usually create a high light. If the high light as shown in the ground glass is over the ridge detail on the skin, a poor photograph will result. If the high light cannot be removed by rearranging the lights, then reflected light should be tried.
In order to effect reflected light a large piece of white paper, cardboard, or similar material is used. A hole is cut in the center of the paper or cardboard. This must be big enough for the camera lens to protrude through. The ends of the paper or board are curved toward the skin or finger to be photographed. The lamps which are to be used are placed facing the curved paper or cardboard in such fashion that the light will strike the paper or board and be reflected by the curved surface to the object.
The lamps should be close enough to the paper or board to give themaximum light. Care should be exercised, however, not to place them too close, because of the fire hazard.
Any arrangement of lamps and reflectors giving a similar effect as the above should prove suitable.
Fingers or skin which have a mottled, reddish-brown color because of decomposition, exposure to severe heat, or diffusion with blood present a problem of lack of contrast between ridges and depressions for photographic purposes. This lack of contrast can be overcome to a large extent by the use of a yellow or light red filter. Sometimes, in those cases where the discoloration is due to the diffusion of blood throughout the tissues, the blood can be washed out by saturating and rinsing the specimen in a 10- to 20-percent solution of citric acid. If, of course, the blood is not removed satisfactorily, the photographing should be done with the filter.
As previously stated, the fingerprint camera can be readily adapted to the use of photographing fingers or skin specimens for ridge detail. Sometimes it is possible to photograph the skin or finger in the same manner as one does a latent print. There will be instances, however, in which the standard use of the fingerprint camera will not be possible or effective, such as for side light, reflected light, and sometimes transmitted light, or instances in which it is not possible to get the finger or skin flush with the opening of the camera. In these instances the lights of the camera are not used, so the batteries should be removed and gooseneck lamps or othersuitable lighting equipment and ground glass utilized when the finger or skin is prepared for photographing (fig. 402).
Fig. 402
[Fig. 402]
The camera is opened either at the point where the lights are housed or at the lens point, whichever is most effective. Then, opening the shutter, the operator moves the camera either toward or away from the finger or skin to the point where the ridge detail is sharpest in the ground glass. The camera is held firmly, the ground glass is removed, the film is inserted and the photograph taken.
With respect to exposure time, it is possible only to generalize and point out that each case will have its own individual aspects. Controlling features for consideration will be the type of film, the type and size of lights, the method of lighting (direct, side, transmitted or reflected) and also whether or not filters are used. Accordingly, there may be a wide variation of exposure time in different cases.