Part 23 (2/2)

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 fas.h.i.+on, the pattern area is cut off and the excess flesh sc.r.a.ped out as before.

While the sc.r.a.ping and cutting are being accomplished, the skin should be soaked and ma.s.saged 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 destroying or 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).

[Ill.u.s.tration: 400. Photograph of charts used in actual case to establish the ident.i.ty of a charred body, victim of murder. Chart A shows skin removed from one of the fingers treated and photographed.

Chart B shows an inked impression of the same finger during victim's life.]

_Water-soaked fingers_

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 tight across 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 gla.s.s 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.

_Drying the fingers_

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 cla.s.sification purposes, the ridge detail should be photographed.

_X-ray photography_

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 bis.m.u.th or lead carbonate, in a thin, even film over the pattern area and then, by the use of the X-ray, reproducing the ridge 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.

_General photography_

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 cla.s.sified. 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.

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