The existence of wrinkles may also cause the impression to acquire an appearance of dissimilarity when compared with the original inked print.
With respect to cases of desiccation, there will probably be shrinkage, hence, the impressions made may appear smaller than in life and the ridges will be finer. In cases in which the epidermis has been lost and there remains only the dermis or second layer, there will usually be shrinkage with the same results. Here also, wrinkles, if present, may cause a difference in appearance from the normal print.
In addition to shrinkage and wrinkles in cases involving the second layer of skin, there is a radical change in the appearance of the ridges themselves. The second or dermal layer of skin is composed of what are called dermal papillae which have the appearance of minute blunt pegs or nipples. The dermal papillae are arranged in double rows (fig. 406). Each double row lies deep in a ridge of the surface or epidermal layer and presents the same variations of ridge characteristics as are on the outer layer of skin except that they are double. Accordingly, when the second layer of skin is printed or photographed, the ridge detail will appear in double. That is, the ridges will appear as though they were split. This may well confuse the fingerprint examiner in that what may be a loop having 10 ridge counts may appear to be a loop having 20 ridge counts when the impression is made from the second or dermal layer of skin. These double rows of ridges are finer and not as sharp as the detail on the outer skin, which adds to the difficulty of arriving at a correct classification and making a proper comparison.
[Fig. 406]
FBI aid
The above techniques and procedures have been dealt with upon the basis that the law enforcement officers would, when a corpse has been found, attempt to secure a set of finger impressions in an effort to identify the unknown dead. If, however, the officer feels that the job is too difficult or is beyond his scope, consideration should be given to cutting off the hands or fingers of the deceased and forwarding them to the Identification Division of the FBI for processing. If this course is decided upon, it is reiterated that local statutes governing the cutting of the dead must be complied with and proper authorization must be secured.
In order to facilitate the transmission of such specimens to the FBI the following suggestions are made:
First, it is deemed most desirable, when possible, to have both of the hands, severed at the wrist, forwarded in their entirety (fig. 407). It is desired that the hands, rather than each separate finger, be sent inasmuch as it eliminates the possibility of getting the fingers mixed up or incorrectly labeled. If, however, it is not possible to send the hands for some reason, then, of course, the fingers should be cut off and forwarded. In cutting, the fingers should be cut off at the palm beginning with the right thumb, then the right index, ring, etc., just as though they were to be printed. As soon as each finger is cut off it should be placed in an individual container, such as a small glass jar, and immediately marked as to which particular finger it is.